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SERVICE MANUAL - Aqua-Hot Heating Systems, Inc.

1. Page 99 Appendix D Extreme Cold Weather Operation Page 100 101 Appendix A Annual Maintenence Page 102 111 O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A This manual 15 designed to aid trained and qualified service technicians with the process of troubleshooting and servicing the Aqua Hot 375D Hydronic Heating System The Aqua Hot features a 12 Volt DC powered Diesel Burner and a 120 Volt AC 1500 Watt Electric Heating Element These two heating sources are used in conjunction with an FDA approved GRAS Generally Recognized as Safe propylene glycol based boiler antifreeze and water heating solution in order to provide a continuous supply of domestic hot water interior fresh water tank heating independent inte rior zone heating Please note that all Danger Warning Caution and Note box es appearing as needed throughout this manual must be reviewed and adhered to during servicing of the Aqua Hot in order to avoid potential hazards which could result in injury death product damage and or property damage Should additional assistance be needed please contact the Technical Support Department at 1 800 685 4298 Monday through Friday between the hours of 7 00 AM and 4 00 PM Mountain Standard Time 2009 Aqua Hot 375D Hydronic Heating System Service Manual
2. Page 94 The Diesel Burner switch has been turned on however multiple attempts are required before the diesel burner will IQNite ccccecceecceeeceeeeeeeeeeeaeeeeeeseeeseeeseeeaees Page 94 The Aqua Hot s exhaust system sputters while the diesel burner is operating Page 94 The Aqua Hot s exhaust system produces white smoke after ignition Page 94 The Aqua Hot s exhaust system produced black smoke after ignition Page 94 The Aqua Hot is operating but an interior and or fresh water tank heating zone is pom eio Eme Page 95 The Aqua Hot is at operating temperature however the interior and or fresh water tank heat exchanger fans are not operating Page 95 The Aqua Hot is operating but the domestic hot water system is not producing __ _ _ _ _ _ _ _ __ _ _ _ 3 _ Page 95 The Electric Element switch has been turned on however the Aqua Hot s 120 Volt AC electric heating element does not operate Page 96 Appendix A Wiring DIAGFlli 2 22 2 31 23 13er es erae eae eoa ees a eua epus doa ca aee st esa tasa oue ebd eae aea cess Page 97 Appendix B Wire Gauge GhaLrt d oid Ede npo eoo 1o Oo quce Co Ceo acon Cone co eo Oo Co eoo Oo Co ao Po sa eo ceo Page 98 Appendix C Winterization
3. JI K Aqua Hot HYDRONIC HEATING SYSTEM 3 75 D Aqua Hot SERVICE MANUAL 2009 Aqua Hot Heating Systems Inc Table of Contents General Information Danger Warning Caution and Note Box Page 6 Section 1 Introduction To The Aqua Hot 375D Technical ON Umm 7 III 180880006 eM MM iL E 8 Agua HotHeater OVEN Page 9 11 Aqua Hot Operational Page 12 Antifreeze and Water Heating 50IV00 ccc ccce cece cece eee eeeeeeeeeesaeeeeeennaes Page 13 14 Section 2 Interior Switch Panel BI UNM 15 EGOITIC S VUBLC Page 15 Switch Panel Wiring 16 Section 3 Exhaust System Exhaust System Requirements esses nennen nennen sanae Page 17 Section 4 Aqua Hot Components _ _ _ _ _ _ _ _ _ _ _ _ __ 32 lt _ _ _ __________ __ ___ _ ___ _ __ _ ___ __ Page 18 ______ Pa
4. Page 64 SECTION 8 DiESEL BURNER COMPONENTS AND REPAIR INFORMATION Escutcheon Plate Spline Nut Escutcheon Plate Fuel Supply Tube Icnition Electrode Adjustment and Cleaning The Ignition Module produces a high voltage spark across the Ignition Electrodes therefore the Ignition Electrodes must be properly adjusted and maintained to ensure that the fuel mix ture 1s ignited when appropriate Adjusting the Ignition Electrodes Using the Beckett T Gauge verify that the Ignition Electrodes are properly adjusted as in Figure 64 If the Ignition Electrodes are not properly adjusted perform the following procedure 1 Slightly loosen the Electrode Clamp retaining screw with a 3 8 inch socket wrench 2 Referencing Figures 63 and 64 properly align the Ignition Electrodes 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A Static Plate Ignition Module Retaining Clips Ignition Module Assembly 3 Tighten the Electrode Clamp Retaining Screw with a 3 8 inch socket wrench 4 Following the replacement procedure for the Igniter As sembly reinstall the Igniter Assembly into the Diesel Burner Cleaning the Ignition Electrodes Polish away any carbon deposits which may have baked onto the metal tips of the Ignition Electrodes with a Scotch Brite pad or similar NOTE After cleaning the Ignition Electrodes verify that the Ignition Electrodes are properly adjusted with the
5. approximately 155 lbs approximately 200 lbs NOTE All vehicle installations must comply with the requirements listed in the Recreational Vehicle Industry Associ ation s RVIA ANSI NFPA 1192 Handbook for Recreational Vehicle Standards To receive a copy of this handbook and other pertinent RVIA Standards write to Recreation Vehicle Industry Association 1896 Preston White Drive P O Box 2999 Reston VA 22090 0999 call them at 703 620 6003 or visit them online at www rvia org Page 7 O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A E SECTION 1 INTRODUCTION TO THE AQUA HorT 3750 Aqua Hot HYDRONIC HEATING SYSTEM For installation only in a compartment that is completely closed off from living quarters and accessible only from the outdoors The Exhaust System MUST NOT terminate beneath the vehicle or under an openable window or vent Combustion Air MUST BE supplied from outside the vehicle A CAUTION THIS APPLIANCE OPERATES ON BOTH AC AND DC POWER USE COPPER CONDUCTORS ONLY Use a 25 Amp fuse for over current protection for the DC power supply Use a circuit breaker that cuts power at 20 Amps maximum for over current protection for the 120 VAC power supply Mount the Heater near a bay storage door so that the Access Cover can be easily removed for service WARNING DO NOT OPERATE APPLIANCE WITH
6. A Using a Volt Meter test for dc voltage at the diesel burner electronic controller at the 45 red wire 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 4 AQUA HoT COMPONENTS If diesel burner motor is running and no volt age 15 present at the 45 wire replace contro ller B Using a Volt Meter check the zone 2 relay for voltage on the 4 pin If there is no voltage at zone 2 relay check wire 45 for damage C Using a Volt Meter check the 2 zone pump for voltage If voltage is present and the pump still fails to operate follow the circulation pump re placement procedure in this book 3 If it is determined that the pump is active verify that the pump is operating properly by checking both connected hoses for heat If both hoses are hot the pump is working properly If one hose is hot or neither hose is hot check the cold hose for a blockage If no blockage exists follow the instructions in this section to replace the Zone pump 2 Page 33 Electrical AC Electric Heating Element The electric heating element uses AC power as an alternate power source for heating the Aqua Hot s boiler tank Troubleshoot the electric heating element if the following condition has occurred e There is a lack of hot domestic water and interior heat when the electric element is selected as the heating source Troubleshooting NOTE For continuous domestic hot w
7. into the Zone calling the Zone calling for for heat heat Page 12 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 SECTION 1 INTRODUCTION TO THE AQUA HorT 3750 Antifreeze and Water Heating Solution As the antifreeze type and mixture ratio is essential to the Aqua Hot s performance and ability to comply with reg ulations the following information is being supplied to understand various types of antifreeze the quality of wa ter necessary and the mixture ratio Aqua Hot Heating Systems Inc recommends CAMCO Ss Boiler Antifreeze 100 F Antifreeze Types The following information addresses the necessary usage of a propylene glycol based boiler type antifreeze in the Aq ua Hot Propylene glycol 1s a safer alternative to the more toxic ethylene glycol antifreeze however as mandated by IAPMO International Association of Plumbing and Mechan ical Officials only those propylene glycol based boiler type antifreezes deemed Generally Recognized as safe GRAS by the FDA should be utilized Because of the significant impact various types of antifreeze can have on a Hydronic heating system including the level of safety provided it has been recognized that there 1s a need to provide an explanation regarding two additional promi nent types of antifreeze coolant available The following information should be utilized as an educational means of ensuring that the proper type of propyl
8. properties they should never be used in the Aqua Hot s Hydronic Heating System Antifreeze Mixture Water Quality In order to ensure maximum performance and longevity of an Aqua Hot heating system s boiler tank and associated components it has been determined that there 1s a need to use distilled de 10nized or soft water 1n combination with concentrated propylene glycol for the Aqua Hot s antifreeze and water heating solution Please note that this is only nec essary when mixing concentrated propylene glycol antifreeze with water suppliers of pre mixed antifreeze are responsible for the use of high quality distilled de ionized or soft wa ter when preparing their antifreeze for sale Hard water possesses a high level of calcium and magnesium ions which deplete the propylene glycol antifreeze s corro sion inhibitors This in turn causes the antifreeze and water heating solution to begin turning acidic which can corrode the Aqua Hot s boiler tank and associated components prem aturely Therefore concentrated propylene glycol should be diluted with distilled de ionized or soft water that 1s 80 ppm or less in total hardness The local water agency should have up to date water quality reports that should indicate if the local tap water 1s within this guideline Antifreeze Terms and Mixture Ratio The following information addresses the process of selecting an antifreeze and water mixture ratio that provides adequate freez
9. sure to disconnect the 120 Volt AC power supply prior to servicing Failure to do so could result in serious personal injury electrical shock or even death Function The Escutcheon Plate Spline Nut secures the Igniter Assembly in place on the Blower Housing Replacement Indicator Replace the Escutcheon Plate Spline Nut if it becomes lost or damaged Replacement Procedure NOTE The Diesel Burner does not need to be detached from the Aqua Hot for this replacement procedure 1 Loosen the Fuel Supply Tube Assembly s hexagonal lock nut on the Fuel Pump Assembly with a 7 16 inch open end wrench Igniter Assembly Escutcheon Plate Spline Nut Fuel Supply Tube s hexagonal locknut to connect to the Igniter Assembly Fuel Supply Tube Fuel Supply Tube s hexagonal locknut to connect to Fuel Pump Assembly Figure 77 Fuel Supply Tube Assembly NOTE The Fuel Supply Tube Assembly does not need to be completely removed from the Fuel Pump Assembly but must be loosened to rotate out of the way 2 Using a 7 16 inch open end wrench remove the Fuel supply Tube Assembly s hexagonal locknut which se cures the Fuel Supply Tube to the Igniter Assembly 3 Remove the Fuel Supply Tube from the Igniter Assembly and rotate out of the way 4 Using a 3 4 inch open end wrench remove the Escutcheon Plate Spline Nut from the Diesel Burner s Escutcheon Plate Fuel Connection 5 Install the repla
10. 3 Check the Aqua Hot s antifreeze and water heating solu tion s ratio of water to propylene glycol The mixture ratio should be approximately 50 50 If the solution is comprised fully of antifreeze 100 the check valves will continue to stick NOTE Storing the motorhome for an extended period of time can cause the check valves to stick If after the initial release of the stuck check valve it contin ues to stick follow the instructions in this section to replace the check valve Page 28 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A Replacement Procedure A DANGER A FAILURE TO DISCONNECT ALL POWER SUPPLIES AND OR TO ALLOW THE HEATER TO COOL BEFORE SERVICING COULD CAUSE SERIOUS DAMAGE OR PERSONAL INJURY 1 Ensure that the Aqua Hot has been completely shut down and that all power sources have been disconnected Also because this replacement procedure will involve the boil er tank and the potential for hot coolant be sure the heat er has adequately cooled 2 Drain the antifreeze and water heating solution from the Aqua Hot s boiler tank using the drain valve 3 Using constant tension pliers loosen and slide back the constant tension clamps securing the hoses to the defec tive check valve 4 Remove the hoses from the defective check valve 5 Remove both the 90 hose barb and the straight hose barb fittings from the defective check valve 2009 Aqua H
11. 375D Hydronic Heating System Service Manual Rev A SECTION 4 AQUA HoT COMPONENTS Zone Relay The Zone relay is an electrical device where the DC circuit 3 On the Fuse block using a volt meter check for 12VDC from the Interior Room Thermostat determines whether the on the C Fuse DC power is permitted to flow to the circulation pump and If no power is present check fuse the heat exchanger fans This allows the Interior Room Thermostat to switch both the fans and circulation pump on 4 On the zone relay check pin 6 for 12 VDC If no power is present inspect wire 24 for damage Troubleshoot the Zone relay if either of the following condi tions have occurred 5 On the Zone relay check pin for 12 VDC If no power is present check E fuse e Interior fans fail to operate 6 On the Zone Relay check pin 0 for ground e circulation pump fails to operate If there is not a ground present verify that the room thermostat is calling for heat and that it is sending a Troubleshooting ground signal to the relay Fans 5 On the zone relay check pin 8 for 12 VDC If no voltage 15 present follow the replacement pro 1 Turn the corresponding room thermostat on on the inte duin cedure for the zone relay in this section rior of the coach ensuring the thermostat is set at the maximum heat setting to ensure they will call for heat 2 Since the Aqua Hot 375D is a hot water priority system make sur
12. Rev A GENERAL INFORMATION Danger Warning Caution and Note Box Definitions Danger Warning Caution and Note boxes appear through out this manual as a means of alerting the service technician to important information A DANGER A Indicates that personal injury is likely or imminent WARNING Indicates that serious damage to the heater will occu and personal injury is possible as well Indicates that damage to the heater is possible NOTE Indicates information that requires special attention by the service technician Page 6 SECTION 1 INTRODUCTION TO THE AQUA HorT 375D M Jn ww Aqua Hot 3 5 AGua Diesel Burner Fuel Consumption Continuous Operation bebo ce Fred a aon ag sies tnt d aepo rut d 0 40 gal hr Heater Voltage Maximum Power Consumption 12 Volt DC 245 watts Ie nene sped Canos avere M situ o earn ee 120 Volt AC 1500 watts ZOnE Heat Circulation Turnip sped CA ONG 2 12 Volt DC 21 watts each Pombero canne 70 e E E DUM ME Maximum of 2 plus Bay Heat Exchanger IDomesuc v Rer Tre ane CAN eee eena E aE Continuous On Demand Ea 16 75 H x 18 W x 29 5 L V6
13. ff a 2 1 NE e iG lt Sy 2 1 3 REC Blower Motor and Blower Wheel af Assembly Coupling Blower Housing Figure 85 Blower Motor Flat of the Blower ON Motor s shaft for the set screw Insert Feeler Gauge between the Blower Wheel and the Access Hole Blower Motor to set screw Page 88 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 SECTION 8 DiESEL BURNER COMPONENTS AND REPAIR INFORMATION Diesel Burner s White Electrical Plug Press back on the tabs to release the white electrical connections Figure 86 Blower Housing Wire Access Hole Blower Motor Wires Input into Blower Housing 1 of 2 bolts to be removed Figure 87 Blower Motor s Wires Page 89 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 SECTION 8 DiESEL BURNER COMPONENTS AND REPAIR INFORMATION Diesel Burner Controller A DAN G R A 2 Locate the white electrical plug connecting the Diesel Burner Controller to the Aqua Hot s wiring harness then The Aqua Hot operates on both AC and DC power Be sure to disconnect the 120 Volt AC power supply prior to press back on the two tabs securing the two connections together Next pull the two electrical plug connections servicing Failure to do so could result in serious personal injury electrical shock or even death completely apart re
14. filling out the contact information for submittal the Aqua Hot will not operate if the access cover is removed The Diesel Burner switch has been turned on however the diesel burner fails to operate 1 Is the Diesel Burner switch s indicator light illuminated A NO a Check for 12 Volt power at the B fuse on the fuse block does it exist c Test the float switch for functionality d Check the Diesel Burner switch for functionality e Check the Interlock switch for functionality B YES a Is the Indicator Light flashing a fault code If so refer to the Switch Panel Blinking Fault Indicator Light section b Check the Control Thermostat The Aqua Hot s normal operating range is 160 190 F for functionality by locating the control thermostat on the heater disconnecting the wires and placing a jumper wire on the harness between wires 10 amp 11 Check the Diesel Burner Controller for functionality f Check the Diesel Burner s Blower Motor for functionality by placing a direct power and ground source to the motor and checking for operation Page 93 O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A UR E d SECTION 10 TROUBLE SHOOTING The Diesel Burner switch has been turned on and the diesel burner s Blower Motor has begun to operate however the diesel burner does not ignite Test both of the Diesel Burner s High Limit Thermostats for co
15. 4 Using a 7 8 socket remove the defective float switch from the Aqua Hot s boiler tank 5 Wrap the threads of the replacement float switch with Teflon tape 6 Screw the replacement float switch into the port on the Aqua Hot s boiler tank and tighten securely with a 7 8 socket ensuring the N O stamp in on top 7 Connect the replacement float switch s wires in the same configuration as the removed float switch s wires 8 Refill the Aqua Hot s Boiler tank with the proper water antifreeze mixture Reference Section 5 in this manual for instructions on filling and draining unit 9 Test for proper operation Be sure to install the replacement float switch with the N O stamp on top failure to do so will allow the diesel electric to come on with no antifreeze in the boiler tank Page 19 Thermostats Control Thermostat Diesel Burner The control thermostat is installed into the Aqua Hot s boiler tank and monitors the temperature of the antifreeze and wa ter heating solution to determine when it is at operating tem perature and when it requires heat The Aqua Hot is consid ered to be at operating temperature between 158 F and 190 F Reference Figure 10 for location Troubleshoot the control thermostat 1f one of the following conditions has occurred e Diesel Burner Fails To operate e There is a lack of hot domestic water and interior heat e Blue or white smoke is expelled from t
16. Secure the Fuel Pump Assembly to the Blower Housing with the two bolts previously removed Fuel Pump Assembly s Fuel Solenoid Valve Fuel Supply Tube Assembly Bolts to be removed on the Fuel Pump Assembly Assembly 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A Fuel uH Cord Set 11 Reattach the Fuel Supply Tube Assembly to the Diesel Burner and Fuel Pump Assembly and tighten both hexago nal locknuts with a 7 16 inch open end wrench 12 Plug the Cord Set back into the Fuel Pump Assembly s Fuel Solenoid Valve 13 Following the procedure for Detaching and Reattaching the Diesel Burner located in Section 7 of this manual reattach the Diesel Burner to the Aqua Hot NOTE The Mounting Gasket must be replaced each time the Diesel Burner is detached from the Aqua Hot refer ence the procedure for Detaching and Reattaching the Diesel Burner located in Section 7 of this manu al for instructions CAUTION Be sure to remove the clamps from the Fuel Supply and Fuel Return lines prior to starting the Diesel Burner Failure to do so could result in serious damage to the Diesel Burner Combustion Air Indicator NN Figure 75 Combustion Air Adjustment Scale on Blower Housing Air Shutter Page 77 SECTION 8 DIESEL BURNER COMPONENTS AND REPAIR INFORMATION Air Band A DANGER A The Aqua Hot operates on both AC and DC pow
17. reinstall the Igniter Assembly Mounting Gasket Air Tube Assembly Figure 58 Fuel Nozzle A DANGER A The Aqua Hot operates on both AC and DC power Be sure to disconnect the 120 Volt AC power supply from the Aqua Hot prior to servicing Failure to do so could result in serious per sonal injury electrical shock or even death Function The Fuel Nozzle atomizes the incoming diesel fuel from the Fuel Pump Assembly in order to reduce the fuel into a fine spray which is mixed with incoming combustion air and then ignited within the Combustion Chamber to heat the Aqua Hot s Boiler Tank Replacement Indicator Replace the Fuel Nozzle if it does not properly spray the diesel fuel in a cone shaped pattern is damaged or clogged or as a part of annual maintenance Reference the Aqua Hot s I D 8 Install anew Mounting Gasket reference the Mounting Gasket Replacement procedure in this section 9 Following the procedure for Detaching and Reattaching the Diesel Burner reattach the Diesel Burner to the Aqua Hot CAUTION Be sure to remove the clamps from the Fuel Supply and Fuel Return lines prior to starting the Diesel Burner Label for nozzle information as well as the Parts Manual in order to ensure that the proper fuel nozzle is used Replacement Procedure NOTE The Diesel Burner does not need to be detached from the Aqua Hot for this replacement procedure Be sure to us
18. uide Blower Housing Cord Set Bolts to be removed on the Fuel Pump Assembly Page 75 O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 8 DIESEL BURNER COMPONENTS AND REPAIR INFORMATION Diesel Burner s white electrical plug Hole in Blower Housing for the Cord Set Fuel Pump Assembly s Fuel Solenoid Valve Cord Set Figure 74 Violet and White wires to Replacement be connected to the Cord Set Diesel Burner s white electrical plug Air Shutter 1 Following the procedure for Detaching and Reattaching A DAN G E qe A the Diesel Burner located in Section 7 of this manual detach the Diesel Burner from the Aqua Hot The Aqua Hot operates on both AC and DC power Be sure to disconnect the 120 Volt AC power supply prior to 2 Unplug the Cord Set from the Fuel Pump Assembly s Fuel servicing Failure to do so could result in serious personal Solenoid Valve injury electrical shock or even death 3 Remove the Fuel Supply Tube Assembly Function A Loosen both hexagonal locknuts on either end of the The Air Shutter helps control the Diesel Burner s combustion Fuel Supply Tube Assembly with a 7 16 inch open air level which mixes with the diesel fuel spray and is ignited end wrench in order to establish a flame to heat the Aqua Hot s Boiler Tank B Pull the Fuel Supply Tube Assembly away from the Diesel Burner Replacement Indicator 4 Using
19. 3 Pull the two connections completely apart Step 4 Remove the fuel lines from the Diesel Burner id E 1 Locate the fuel pump assembly on the diesel 2 Using an 11 16 wrench loosen the nuts securing burner and the corresponding fuel lines each fuel line to the fuel pump assembly Page 54 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 SECTION 7 DETACHING AND REATTACHING THE DIESEL BURNER Step 5 Remove the Diesel Burner from the Aqua Hot Se VTA A 7 A r p as 1 The Diesel Burner is secured to the Aqua Hot with 2 Carefully lift the Diesel Burner away from the Aq three nuts that can be removed by using a 9 16 ua Hot inch socket wrench with a wobble extension Figure 44 NOTE It may be necessary to move the Diesel Burner s Ignition Module back out of the way in order to access the top bolt Reference Section 8 of this manual for instructions 3 Remove the Mounting Gasket from the boiler tank s front plate and the Diesel Burner Page 55 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 SECTION 7 DETACHING AND REATTACHING THE DIESEL BURNER Instructions for Reattaching the Diesel Burner Step 1 Replace the Mounting Gasket ay p Ey c FENCE NS gt gt X gt D B oy AS e 1 Clean the boil
20. A DANGER A The Aqua Hot operates o both AC and DC power Be sure to disconnect the 120 Volt AC power supply from the Aqua Hot prior to servicing Failure to do so could result in seri ous personal injury electrical shock or even death Function The Air Tube Assembly houses the Igniter Assembly and helps to control the flame produced by the Diesel Burner Replacement Indicator Replace the Air Tube Assembly if it is broken or cracked Replacement Procedure CAUTION Be sure to clamp off the Fuel Supply and Return lines prior to beginning this replacement procedure 1 Following the procedure for Detaching and Reattaching the Diesel Burner located in section 7 Detach the Die sel Burner from the Aqua Hot 2 Remove the Mounting Gasket from the Air Tube Assem bly 3 Remove the Igniter Assembly from the Diesel Burner reference the Igniter Assembly Replacement procedure located in this section 4 Remove all screws and bolts securing the Air Tube As sembly to the Diesel Burner s Blower Housing Page 61 O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 8 DIESEL BURNER COMPONENTS AND REPAIR INFORMATION 5 Remove the Air Tube Assembly from the Diesel Burner 6 Attach the replacement Air Tube Assembly to the Diesel Burner s Blower Housing and secure all screws and bolts previously removed 7 Following the Igniter Assembly Replacement procedure
21. Assembly 180 from the installed position while removing the Igniter Assembly from the Air Tube Assembly If it continues to be difficult to re move the Igniter Assembly the Escutcheon Plate screw securing the Escutcheon Plate to the Blower Housing can be removed however be sure to align the edge of the Escutcheon Plate back to the edge of the label and secure with the Escutcheon Plate screw Using a 3 4 inch wrench hold the Igniter Assembly at the base of the Fuel Nozzle next to the Static Plate while loosening the Fuel Nozzle with a 5 8 inch open end wrench Remove the defective Fuel Nozzle from the Igniter Assem bly O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 9 Install the replacement Fuel Nozzle onto the Igniter As sembly and tighten NOTE Be sure to tighten the Fuel Nozzle loosen it 1 4 turn 10 11 12 13 and then firmly retighten This will establish a seated fit and avoid any leaks The Ignition Electrodes may need to be adjusted after replacing the Fuel Nozzle reference the Igniter As sembly information in Section 8 for the Ignition Elec trode Adjustment procedure Insert the Igniter Assembly back into the Air Tube Assem bly and align the Fuel Supply Tube back with the Escutch eon Plate Tighten the Escutcheon Plate Spline Nut onto the Fuel Supply Tube to secure it into place Close the Ignition Module and secure with the Ignition Module R
22. Beckett T Gauge adjust 1f needed Page 65 L A v M SECTION 8 DiESEL BURNER COMPONENTS AND REPAIR INFORMATION Figure 64 1 4 ABOVE NOZZLE CENTER Proper placement of the Igniter 1 8 NOZZLE TO TIP Assembly s Ignition Electrodes SPACING GAP MARKS URI SNH 3 N 31 5 U 2 1 57 m E 2 T gt UU 38 ELECTRODE POSTON 5 o 2 i 4 4 F HEADS m SA 7 gt gt gt d z gt A 4 2 S E gt 2 PRI Figure 63A Figure 64A Tip Gap top view 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 099 L M Page 66 SECTION 8 DiESEL BURNER COMPONENTS AND REPAIR INFORMATION Ignition Module Assembly 2 Using a Molex Pin Extractor tool remove the Igniter As sembly s two wires from the 5 and the 6 Terminals on A DAWN G E Re A the Diesel Burner s white electrical plug reference figure The Aqua Hot operates on both AC and DC power Be sure 34 to disconnect the 120 Volt AC power supply prior to servic NECS QUI ANU AWAY AO MINE NCSC s SEMEL erence Figure ing Failure to do so could result in serious personal injury electrical shock or even death 4 Remove the Ignition Module Assembly by loosening the two screws securing it
23. Block for the zone pumps 56 WHT a If No voltage replace the fuse b If Yes continue B Using a Volt Meter Check and ensure that the zone relay is sending voltage to the pump at pin 4 a If No voltage is present troubleshoot the zone relay b If Yes continue C Check the Zone pump for voltage a If there 15 voltage and the zone pump 15 not operating follow the zone pump re placement procedure in this book The zone pump can be tested by connecting it to an external 12 Volt DC power source to verify that the pump is defective Page 31 SECTION 4 AQUA HoT COMPONENTS Replacement Procedure 6 Remove the hoses from the defective zone pump A DANG 6 Slide the hoses back onto the replacement zone pump FAILURE TO DISCONNECT ALL POWER SUPPLIES AND OR and set the constant tension clamps back into place TO ALLOW THE HEATER TO COOL BEFORE SERVICING COULD CAUSE SERIOUS DAMAGE OR PERSONAL INJURY 7 Install the replacement zone pump onto the heater by aligning nylatch plungers into holes and pushing in but Ensure that the Aqua Hot has been completely shut ton to secure pump down and that all power sources have been disconnect ed Also because this replacement procedure will in 8 Reconnect the wires on the replacement zone pump to the volve the potential for hot coolant be sure the heater is wires connected to the heater by uniting the red quick adequately cooled disconnect terminals
24. Controller Page 60 SECTION 8 DIESEL BURNER COMPONENTS AND REPAIR INFORMATION Mounting Gasket A DANGER A The Aqua Hot operates on both AC and DC power Be sure to disconnect the 120 Volt AC power supply from the Aqua Hot prior to servicing Failure to do so could result in serious personal injury electrical shock or even death Function The Mounting Gasket creates a tight seal between the Combus tion Chamber and the Diesel Burner Mounting Plate Replacement Indicator The Mounting Gasket should be replaced each time the Diesel Burner is detached from the Aqua Hot Replacement Procedure CAUTION Be sure to clamp off the Fuel Supply and Return lines prior to beginning this replacement procedure 9 1 Follow the Detaching and Reattaching the Diesel Burner procedure located in Section 7 of this manual 2 Remove the existing Mounting Gasket from the Boiler Tank s front plate and from the Diesel Burner Mounting Plate Be sure to clean the old gasket completely off of both plates 3 Set the replacement Mounting Gasket into place on the Boiler Tank s front plate 4 Following the procedure for Detaching and Reattaching the Diesel Burner reattach the Diesel Burner to the Aqua Hot CAUTION Be sure to remove the clamps from the Fuel Supply and Fuel Return lines prior to starting the Diesel Burner Mounting Gasket Diesel Burner Mounting Plate Air Tube Assembly
25. Diesel Burner must be utilized 1 Is the Diesel Burner activated 2 Is the Diesel Burner operating Properly 3 Was the heating system properly installed following the 375d installation manual A there at least 5 heat exchangers installed in the Interior of the motor home B Are there cold air returns installed for every heat exchanger Refrence Figure 92 C Are the heat exchangers mounted as close to the hot air outlet grill as possible Reference Figure 91 4 If the answers to the above questions are all yes refer to section 10 Trouble Shooting Guide for a lack of interior heat Return Air 9 gt Indicates generally recommended locations for the Cozy at Exchangers e RC EX f 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A Figure 91 CABINET COUCH HEAT EXCHANGER REGISTER uw Frye M v LT COLD AIR REGISTER HOT AIR OUTLET Return Air A mi Page 101 General Recommended Maintenance Annually To keep the Aqua Hot running smoothly it is ideal to have the Diesel Burner tuned up annually A tune up should consist of a new Fuel Nozzle and Fuel Filter along with a thorough cleaning of the Combustion Chamber if necessary reference Figure To ensure maximum Diesel Burner performance always use the recommende
26. Ignition Module Assembly back on its hinge 2 Using a Molex Pin Extractor Tool remove the Flame Sen sor Socket s two wires from the 1 and 2 terminals on the Diesel Burner s white electrical plug reference Figure 13 and Appendix A Remove the Flame Sensor Socket from the underside of the Ignition Module Assembly by loosening the Flame Sensor Gasket from the tabs and sliding the Flame Sensor s Mounting Bracket forward until it 1s free from the clip on the Ignition Module Assembly Then lift the Flame Sensor Socket and the attached Gasket away from the Ignition Module Assembly 4 Remove the Flame Sensor Gasket from the defective Flame Sensor Socket and slide it onto the replacement Flame Sen sor Socket ensuring that the flat bottom of the Flame Sen sor Gasket 1s level with the Flame Sensor s Mounting Bracket Page 70 SECTION 8 DIESEL BURNER COMPONENTS AND REPAIR INFORMATION 5 Insert one of the Flame Sensor Socket s wires into Terminal 1 7 and the other wire into Terminal Z2 on the Diesel Burner s white electrical plug reference Figure 34 NOTE The Flame Sensor Socket s wires are not polarity sensitive therefore either wire can be inserted into Termi nals 1 and 2 8 6 Setthe Flame Sensor Socket back into place by tilting the Flame Sensor Socket up at an angle to slide under the clip then 9 set the Flame Sensor Socket and Mounting Bracket flat against the Ignition Module Assembly Secure
27. defective high limit thermostat to the replacement high limit thermostat 6 Test for proper operation Figure 15 DC High Limit Thermostats LL messi Button Page 26 Low Temperature Cutoff Thermostat The low temperature cutoff thermostat operates the domestic water priority system by blocking the interior heating feature when domestic hot water is being used This ensures that even heat is provided for domestic hot water which avoids the possibility of cold water pockets during showers etc Troubleshoot the low temperature cutoff thermostat if the following conditions have occurred e Thereisa lack of interior heat e There is a lack of hot water Troubleshooting 1 Determine if the conditions are right for the Low Temp Cutoff Thermostat to be reset A Verify that the Aqua Hot is at operating temperature between 158 F and 190 F B Verify that the domestic hot water is not being used 2 Ifthe Low Temp Cutoff is not reset 1 6 has continui ty after it has been determined that it should be com plete the following A Using a temperature sensor verify that the low temperature cutoff thermostat is above 100 F If the thermostat is below 90 F verify that the Aqua Hot is up to operating temperature and that a hot water faucet 1s not leaking B Disconnect the low temperature cutoff thermostat s wires from the Aqua Hot s wiring harness then jump the wiring harness wires
28. died dcn A qud Page 68 69 Flame Sensor and Flame Sensor Page 70 71 IUe SUpDIy TUDe ASSEITIDLIV I Page 72 my es ULM Al Olay cohol 0 __ ___ _3 23 2 222 2 lt 6 Page 72 74 COE MONET 75 76 2 2 2 2223 2 322 _ _ _ _ Page 76 77 A D RU T T T T e T NN Page 78 79 Escutcheon Plate 80 ESCUICheoOr FIATO N 81 Clim ero cher 82 83 84 E ea Saeed acted a Gated 85 NIOLO E 86 89 Diesel Burner COMMU ONG tuna 90 Section 9 Switch Panel Blinking Fault Indicator Light DIeseleButrner raul e odes Page 91 92 O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A Table of Contents Section 10 Troubleshooting The Diesel Burner switch has been turned on however the diesel burner fails Page 93 The Diesel Burner switch has been turned on and the diesel burner s Blower Motor has begun to operate however the diesel burner does not ignite
29. for the thermostat together to bypass the thermostat Wires 23 amp 24 If the Heater works properly with the thermo stat bypassed follow the instructions in this section to replace the low temperature cutoff thermostat 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 4 AQUA HOT COMPONENTS 3 If the Low Temp Cutoff Thermostat Does not trip when domestic hot water is being used or when the Aq ua Hot falls below operating temperature complete the following A Using a temperature sensor verify that the low temperature cutoff thermostat 1s below 90 F which is necessary for the thermostat to trip B Inspect the wiring to ensure that the Aqua Hot 15 wired properly and that the low temperature cutoff thermostat has not been bypassed via jumper wires C Ensure the Domestic water lines have been plumbed properly into and out of the heater Replacement Procedure A DANGER A FAILURE TO DISCONNECT ALL POWER SUPPLIES AND OR TO ALLOW THE HEATER TO COOL BEFORE SERVICING COULD CAUSE SERIOUS DAMAGE OR PERSONAL INJURY 1 Ensure that the Aqua Hot has been completely shut down and that all power sources have been discon nected 2 Locate the low temperature cutoff thermostat on the cold domestic water inlet pipe on the Aqua Hot 3 Disconnect the defective low temperature cutoff thermo stats wires by separating the quick disconnect termi nals 4 Using a 5 8 wrench or
30. from the Fuel Pump Assembly but must be loosened to rotate out of the way Figure 78 2 OF LABEL 7 Escutcheon Be sure the Escutcheon Plate is Plate reset to the edge of the label on the Blower Housing Page 81 O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 SECTION 8 DIESEL BURNER COMPONENTS AND REPAIR INFORMATION Igniter Assembly Escutcheon Plate Escutcheon Plate Spline Nut Fuel Supply Tube s knurled locknut to connect to the Igniter Assembly N Ge m ki Escutcheon Plate Bolt to be z a removed when replacing Escutcheon Plate Escutcheon Fuel Supply Tube s Sf Plate knurled locknut to connect to Fuel Pump Assembly Fuel Supply Figure 79 Tube Assembly Replacement Procedure Air Guide CAUTION CAUTION The Aqua Hot operates on both AC and DC power Be Be sure to clamp off the Fuel Supply and Return lines prior to beginning this replacement procedure sure to disconnect the 120 Volt AC power supply prior to servicing Failure to do so could result in serious personal 1 Following the procedure for Detaching and Reattaching injury electrical shock or even death the Diesel Burner located in Section 7 of this manual detach the Diesel Burner from the Aqua Hot Function 2 Move the Blower Motor and attached Blower Wheel back The Air Guide in conjunction with the Air Shutter and Air from the Diesel Burner Band helps control the
31. input voltage is checked to ensure that it is greater than 10 volts 16 The Diesel Burner Controller continues to run through a cycle of the following checks until one of these scenarios does not check out checking for a flame checking that the Control Thermo stat is still calling for heat checking that the Interior Switch Panel s Diesel Burner switch is still in the ON position checking that the input voltage is greater than 10 volts 17 The Diesel Burner begins a shutdown procedure when one of the following occurs the flame extinguishes the Control Thermostat signals that there is no longer a need for heat the Diesel Burner switch is turned OFF the input voltage drops below 10 volts Page 45 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 6 DiESEL BURNER 23 The Diesel Burner Controller ensures that the current flow to the Blower Motor has ceased 18 The Fuel Pump Assembly is deactivated 24 The Diesel Burner Controller ensures that the current flow to the Fuel Pump Assembly s Fuel Sole 19 The Flame Sensor verifies that noid Valve has ceased the flame has been extinguished 26 The Diesel Burner Controller ensures that the current flow to the Ignition Module has ceased 20 The Control Thermostat is checked to determine if there is a need for additional heat 27 The Control Thermostat is 21 A 30 second to 2 min
32. ohms Cleaning Tips Maintenance For light dirt dust and or carbon deposits simply wipe off the Flame Sensor with a soft cloth Flame Sensor Replacement Procedure NOTE The Diesel Burner does not need to be detached from the Aqua Hot for this replacement procedure 1 Loosen the two screws securing the Ignition Module Re taining Clips and rotate both clips to release the Ignition Module Assembly Then tilt the Ignition Module Assembly back on its hinge O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 2 Supporting the Flame Sensor Socket and the Flame Sensor Gasket pull the defective Flame Sensor straight out from the Flame Sensor Socket 3 Insert the replacement Flame Sensor s pins into the Flame Sensor Socket and push the Flame Sensor firmly into place 4 Re test the Flame Sensor for resistance reference the Component Test in this section NOTE If the Flame Sensor continues to register resistance when exposed to a light source the Flame Sensor and Flame Sensor Socket must be replaced reference the Flame Sensor Socket Replacement Procedure in thi section for instructions Flame Sensor Socket Replacement Procedure NOTE The Diesel Burner does not need to be detached from the Aqua Hot for this replacement procedure 1 Loosen the two screws securing the Ignition Module Re taining Clips and rotate both clips to release the Ignition Module Assembly Then tilt the
33. the Diesel Burner reattach the Diesel Burner to the Aqua Hot 6 Secure the replacement Air Guide to the Blower Housing NOTE The Mounting Gasket must be replaced each time the with the two screws previously removed Diesel Burner is detached from the Aqua Hot refer ence the procedure for Detaching and Reattaching 7 Ifapplicable return the Air Band to its original configura the Diesel Burner located in Section 7 of this manu tion and secure it in place with the nut and bolt previously al for instructions removed 8 Insert the Blower Motor and Blower Wheel Assembly into CAUT 1 gt the Blower Housing and secure it with the two bolts previ Be sure to remove the clamps from the Fuel Supply and Fuel ously removed Return lines prior to starting the Diesel Burner Figure 80 Blower Motor and Blower Wheel Assembly A M c 4 W Coupling Air Guide Blower Housing 1 of 2 screws securing the Air Guide to the Blower Housing Air Band Page 83 O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A E SECTION 8 DIESEL BURNER COMPONENTS AND REPAIR INFORMATION Coupling 4 Takethe replacement Coupling and insert it into the Blow er Housing under the Air Guide and slide it onto the Fuel A DAWN G E R A Pump Assembly s shaft The Aqua Hot operates on both AC and DC power Be sure to disconnect the 120 Volt AC power supply prior to NOTE It may be necess
34. the set screw 15 centered on the flat of the Blower Motor s shaft Using the hexagonal wrench tighten the set screw to se cure the Blower Wheel in place 7 Insert the Blower Motor and Blower Wheel Assembly into the Blower Housing and secure it with the two bolts previ ously removed NOTE The Blower Motor and Blower Wheel Assembly con nects with the Coupling which connects to the Fuel Pump Assembly within the Diesel Burner s Blower Housing therefore it may be necessary to pull the Ignition Module Assembly back on its hinge and ro tate the Blower Wheel slowly until the Blower Motor is seated correctly on the Coupling and moves into place 8 Following the procedure for Detaching and Reattaching the Diesel Burner located in Section 7 of this manual reattach the Diesel Burner to the Aqua Hot NOTE The Mounting Gasket must be replaced each time the Diesel Burner is detached from the Aqua Hot refer ence the procedure for Detaching and Reattaching the Diesel Burner located in Section 7 of this manu al for instructions CAUTION Be sure to remove the clamps from the Fuel Supply and Fuel Return lines prior to starting the Diesel Burner NC Blower Motor and Blower Wheel Assembly Figure 82 Page 85 SECTION 8 DIESEL BURNER COMPONENTS AND REPAIR INFORMATION Blower Motor WARNING Use CAUTION when testing the Diesel Burner while the Inte rior Switch Panel s Diesel Burn
35. to the Diesel Burner Blower Hous Function 105 The Ignition Module s Igniter produces a high voltage ignition 4 Secure the replacement Ignition Module Assembly to the spark approximately 20 000 volts which 1s released across the TETOVE metal tips of the Igniter Assembly s Electrodes during the Diesel NOTE It may be necessary to clip off and remove the wire Burner s initial start up This spark ignites the incoming fuel air ties bundling the Diesel Burner components wires mixture which produces a flame to heat the Aqua Hot s Boiler together in order to free the Cord Set for removal Tank Replacement Indicator 5 Insert the replacement wires thru the Blower Housing and Replace the Ignition Module Assembly if it becomes cracked or tS EE vires ANUS damaged if the Igniter 15 unable to produce a spark across the Pug dre SEC WHS Igniter Assembly s Blectrodes and the black wire should be inserted into the 6 terminal on the Diesel Burner s white electrical plug reference Replacement Procedure Figure 34 and Appendix A NOTE The Diesel Burner does not need to be detached from Close the Ignition Module Assembly and secure with re taining clips previously released Tighten screws the Aqua Hot for this replacement procedure 1 Loosen the two screws securing the Ignition Module Retain 7 Test
36. water heating solution from the Aqua Hot s boiler tank using the drain valve 3 Remove the diesel Burner Reference Section 7 4 Remove the two wires secured to the defective electric heating element by cutting them with wire cutters 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 4 AQUA HOT COMPONENTS 10 11 Using a 7 8 inch socket remove the defective electric heating element from the Aqua Hot s boiler tank Wrap the new electric element threads with Teflon tape Install the replacement 1500 watt electric heating ele ment into the boiler tank Connect the wires removed from the defective electric heating element to the replacement electric heating ele ment utilizing crimp terminals Reinstall the diesel burner Refill the Aqua Hot s boiler tank with the antifreeze and water heating solution Reference Section 5 Test for proper operation Figure 21 Page 35 AC Relay The AC relay is an electrical device where the DC circuit from the electric switch determines whether the AC power 1s permitted to flow to the electric heating element This al lows the 12 VDC electric switch to switch the 120 VAC electric heating element on and off in conjunction with the interior switch panel and control thermostat even though the electric heating element is on a separate circuit Troubleshoot the AC relay if the following condition has occurred e The elec
37. 009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 SECTION 4 AQUA HoT COMPONENTS Thermostats continued If the Electric Element is not within spec check the fol Control Thermostat Electric Element EPUM owing The control thermostat is installed on the Aqua Hot s boiler tank and monitors the temperature of the antifreeze and wa A D AN G f R A ter heating solution to determine when it is at operating tem perature and when it requires heat The Aqua Hot 1s consid FAILURE TO DISCONNECT ALL POWER SUPPLIES AND OR TQ ered to be at operating temperature between 158 F and 190 ALLOW THE HEATER TO COOL BEFORE SERVICING COULI F CAUSE SERIOUS DAMAGE OR PERSONAL INJURY Troubleshoot the electric element control thermostat 1f one of e A Verify that the temperature of the boiler tank has the following conditions has occurred fallen below the 158 F minimum operating temper ature by checking with a digital thermometer e The Electric Element Fails To operate e There isa lack of hot domestic water and interior heat B Disconnect the control thermostat s wires 52 amp 54 from their connections and using an ohmmeter check for continuity on the control thermostat NOTE For continuous domestic hot water to be present the diesel burner must be selected also as a heat ing source If there is no continuity follow the instructions in this section for repl
38. 2 Drain the antifreeze and water heating solution from the 9 Refill the Aqua Hot s boiler tank with the antifreeze and Aqua Hot s boiler tank using the drain valve water heating solution Reference Section 5 for filling 1 nstructions 3 Disconnect the defective zone pump s wires by separat ing the quick disconnect terminals Reference Figure 10 Test the Aqua Hot for normal operation 19 4 Release the nylatch plungers securing pump to heater 5 Using constant tension pliers loosen and slide back the constant tension clamps securing the hoses to the zone pump Figure 19 Zone Pump 2 i A Zone Pump 1 Page 32 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 Figure 20 Stir Pump Zone Pump 2 The stir pump circulates the antifreeze and water heating solution within the Aqua Hot s boiler tank in order to ensure even heating of the solution To accomplish this the stir pump draws the solution from the bottom of the tank and deposits it back into the top of the tank after circulation through heating loop number 2 Troubleshoot the stir pump if the following condition has occurred e There isa lack of hot domestic water Troubleshooting NOTE In order for the stir pump to operate the diesel burner motor must be running 1 Verify that the Diesel Burner motor is running 2 Ifthe diesel burner motor is running and the stir pump still 1s not operating
39. ACCESS COVERS REMOVED Minimum Heater Clearances Front Open Access Back 0 inches Top 6 inches Install in strict compliance with local codes NFPA 1192 and the manufacturer s instructions WTERTE Certified for use in a Recreational CI Vehicle ONLY C US Direct Vent Appliance 3069328 Maximum Tank Watts DC Watts AC Pressure 35 60 12 VDC 120 VAC 50 60 Hz Nozzle Size Angle Volts Volts 59 000 BTU 17 3 kWh 145 PSI 10 0 bar Input Firing Rate Pump Pressure Diesel Burner Diesel Burner Fuel Type Model Number Serial Number aas 1 J Model Number Serial Number Manufactured Date 15549 East Highway 52 Fort Lupton CO 80621 1 800 685 4298 www aqua hot com For installation only in a compartment that is completely closed off from living quarters and accessible only from the outdoors The Exhaust System MUST NOT terminate beneath the vehicle or under an openable window or vent Combustion Air MUST BE supplied from outside the vehicle CAUTION THIS APPLIANCE OPERATE ON BOTH AC AND DC POWER USE COPPER CONDUCTORS ONLY Use a 25 Amp fuse for over current protection for the DC power supply Use a circuit breaker that cuts power at 20 Amps maximum for over current protection for the 120 VAC power supply Mount the Heater near a bay storage door so that the Access Cover can be easily removed for service WARNING DO NOT OPERATE APPLIANCE WITH ACCESS COVERS REMOVED Minimum Heater Clearance
40. Clean the Combustion chamber 1 Remove The Diesel Burner A Unplug Diesel Burner controller NOTE Before Disconnecting Fuel lines going to Diesel Burner it is recommended to pinch off the fuel lines coming into the heater Figure 95b B Disconnect Fuel Lines C Remove nuts securing the Diesel Burner and remove 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A D Remove Gasket and inspect for signs of damage Page 104 APPENDIX E ANNUAL MAINTENANCE PROCEDURE 2 Remove The Flame Tube A Loosen and Remove the four 5 16 24 nuts securing the Flame Tube in place B Remove the Fame Tube Spacer C Remove the Flame Tube D Clean and inspect the Flame Tube E Clean and inspect the Heat Transfer Tabs welded inside the Aqua hot using a long handled wire brush F Clean and inspect the Flame Tube Spacer Flame Tube Flame Tube Flame Tube Spacer Gasket Page 105 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 APPENDIX E ANNUAL MAINTENANCE PROCEDURE 3 Reinstall The Combustion Chamber NOTE The Two Flame Tube Mounting Gaskets should be replaced each time the Flame Tube is de tached from the Aqua Hot A Install the 1st Flame Tube Mounting Gasket on to the boiler tank B Install the Flame Tube into the Boiler Tank C Install the 2nd Flame Tube Mounting Gasket onto the Flame Tube Assembly D Inst
41. Diesel Burner s Combustion Air level which mixes with the diesel fuel spray and is ignited in order to A Using a 3 8 inch socket wrench loosen and remove establish a flame to heat the Aqua Hot s Boiler Tank the two bolts securing the Blower Motor s plate to the Blower Housing Replacement Indicator B Pull the Blower Motor and Blower Wheel Assembly Replace the Air Guide if it becomes cracked broken or dam out of the Blower Housing and away from the Diesel aged Burner being careful not to dislodge the Blower Mo tor s wiring Page 82 O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A E SECTION 8 DIESEL BURNER COMPONENTS AND REPAIR INFORMATION 3 Usinga Phillips screwdriver remove the two screws se NOTE In order to connect the Fuel Pump Assembly to the curing the Air Guide in place on the Blower Housing Blower Motor with the Coupling it may be necessary to pull the Ignition Module Assembly back on its hinge and rotate the Blower Wheel slowly until both NOTE It may be necessary to remove the nut and bolt from the Air Band and rotate the Air Band slightly in order the Blower Motor and Fuel Pump Assembly are seat to access the Air Guide s screws ed correctly on the Coupling 4 Remove the defective Air Guide from the Diesel Burner 9 Following the procedure for Detaching and Reattaching the Diesel Burner located in Section 4 of this manual 5 Install the replacement Air Guide onto
42. ETACHING AND REATTACHING THE DIESEL BURNER Step 5 Reinstall the Access Cover s2Aqua Hot HYDRONIC HEATING SYSTEM 375 D 1 Set the access cover back into place on the Aqua Hot 2 Insert the bolts in the two locations on the Aqua Hot to se cure the cover in place tighten the bolts securely NOTE The access cover must be installed prior to operation as a safety switch exists which will prevent the Aqua Hot from operating whenever the access cover is not proper ly installed CAUTION Be sure to remove the clamps from the Fuel Supply and Return lines prior to starting the Diesel Burner Failure to do so could result in serious damage to the Diesel Burner Page 59 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 SECTION 8 DIESEL BURNER COMPONENTS AND REPAIR INFORMATION Diesel Burner Components gt gt gt Mounting Gasket 2 Air Tube Assembly Prep Fuel Nozzle Igniter Assembly Ignition Module Assembly Ignition Module Gasket Kit Flame Sensor Flame Sensor Socket Fuel Supply Tube Fuel Pump Assembly 2009 Aqua Hot 3750 Hydronic Heating System Service Manual Rev A T2 erence Air Shutter 18 dde Air Band jr e Escutcheon Plate Spline Nut Escutcheon Plate Blower Housing Air Guide 20 Blower Motor 21 2 55 Diesel Burner
43. Fault Code 1 1 Check the supply voltage is it above 11 1 2 Does the voltage remain above 11 1 throughout the Diesel Burner s cycle Fault Code 2 1 Check the Blower Motor for an external short Fault Code 3 1 Check the Fuel Solenoid for an external short Fault Code 4 1 Check the Ignition Module for an external short 2 Check the 15 Pin Connector to the Diesel Burner Controller for contamination Page 91 O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 9 SWITCH PANEL BLINKING FAULT INDICATOR LIGHT Fault Code 5 1 Check the Ignition Module for an external short 2 Check the Blower Motor for an external short Fault Code 6 1 Did the left High Limit Thermostat connected to wires 15 and 16 trip 2 Is The insulation surrounding the Aqua Hot Boiler Tank shorting out the thermostat to ground Fault Code 7 1 Check the Fuel Solenoid for an external short 2 Is The insulation surrounding the Aqua Hot Boiler Tank shorting out the thermostat to ground Fault Code 8 Did the right High Limit Thermostat connected to wires 8 and 21 trip Check the vehicle s fuel supply Check the Fuel Solenoid Check the Fuel Nozzle Is the insulation surrounding the Aqua Hot Boiler Tank shorting out the thermostat to ground MU o up Fault Code 9 Is the Flame Sensor Lens clean Is there too much combustion air for the Diesel Burner Check the Fuel Nozzle I
44. LOW CHART Diesel Burner Electric Element Switch Turned ON Switch Turned Diesel Burner heat Electric Heating source selected by Element heat source Diesel Burner switch selected by Electric Element switch Diesel Burner fires into the Combustion Electric Heating Chamber which Element activates heats the antifreeze which heats the and water heating antifreeze and water solution in the Boiler heating solution in Tank the Boiler Tank 10 20 Minutes 1 2 Hours Boiler Tank heats to 190 F A hot water faucet e g kitchen sink shower etc calls for hot water Zone Thermostat calls for heat The Circulation Pump activates for the Zone which called for heat The heated antifreeze and water heating solution is trans ported throughout the plumbing lines in that zone Heat is transferred to the Domestic Water System Continuous hot water is supplied to the faucet NOTE The Diesel Burner and or Electric Heating Element as switched ON will automatically begin Heat fans reheating the antifreeze and water heating solution when the Boiler Tank drops below 160 F NOTE The heat exchang ers fans will not operate until the Boiler tank reach fe es a minimum of 150 antifreeze and water heating solution is imer to the Boiler Chart 1 Tank to be reheated Antifreeze and water heating solution moves through the Heat is transferred Heat Exchangers in
45. N D C 1 6 C FES 1 21 o fu 7 2C 6 NA 9 gt Lj 20 eins a X E 3 uU gt dE d o mMm 28 3 2 m 22 2 amp 5 CI Figure 100b B Using a 3 4 and a 5 8 wrench remove and replace the fuel nozzle Figure 101b B Adjust the Height of the Electrodes using the Beckett T Gauge NOTE Be sure to tighten nozzle completely to prevent fuel leakage Page 109 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 APPENDIX E ANNUAL MAINTENANCE PROCEDURE 4 Reinstall Igniter Assembly NOTE Verify that the Escutcheon Plate 1s adjusted to the edge of the label affixed to the Blower Housing A Insert Igniter Assembly into the blower housing B Install the Escutcheon Plate and Escutcheon Plate Spline Nut ensuring the Escutcheon Plate 15 adjusted to the edge of the label affixed to the Blower Housing Then Securely tighten Fuel High Pressure Pipe C Close Ignition Coil D Using a flat head screw driver Securely Tighten the retaining clips securing the ignition coil in place Page 110 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 APPENDIX E ANNUAL MAINTENANCE PROCEDURE 6 Test for proper operation 10 General Recommendations For The Customer A Turn the Diesel Burner switch on and let heater run for a complete cycle A Tune up Diesel Burner Annually B After the Diesel Bu
46. NENTS AND REPAIR INFORMATION 3 Remove the Fuel Supply Tube Assembly A Loosen both hexagonal locknuts on either end of the Fuel Supply Tube Assembly with a 7 16 inch open end wrench B Pull the Fuel Supply Tube Assembly away from the Diesel Burner 4 Using a 3 8 inch socket wrench remove the two bolts se curing the Fuel Pump Assembly to the Blower Housing 5 Pull the Fuel Pump Assembly straight out from the Blower Housing NOTE The Coupling may remain attached to the Fuel Pump Assembly upon removal from the Diesel Burner 6 Insert the replacement Fuel Pump Assembly and attached Coupling if applicable into the Blower Housing NOTE In order to connect the Fuel Pump Assembly to the Blower Motor with the Coupling it may be necessary to pull the Ignition Module Assembly back on its hinge and rotate the Blower Wheel slowly until both the Blower Motor and the Fuel Pump Assembly are seated correctly on the Coupling The Mounting Gasket must be replaced each time the Diesel Burner is detached from the Aqua Hot refer ence the procedure for Detaching and Reattaching the Diesel Burner located in Section 4 of this manu al for instructions Page 73 SECTION 8 DIESEL BURNER COMPONENTS AND REPAIR INFORMATION 7 Secure the replacement Fuel Pump Assembly to the Blow 9 Plug the Cord Set back into the Fuel Pump Assembly s er Housing with the two bolts previously removed Fuel Solenoid Valve 8 Re
47. NS 0 TOTAL CONDUCTORS SIZES FOR 3 DROP IN VOLTAGE CURRENT Length of Conductor from Source of Current to Device and back to Source Feet ON CIRCUIT IN AMPS 10 15 20 25 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 12 Volts 3 Drop Wire Sizes gage Based on Minimum CM Area e lt C e e Em ERES fool ole fe ela bee fol Telefe eH n nm 2 6 6 IL mm mpm folate fe ele a 2 LLC n nmm n m m 9 mPa Te foe Peta Pa Le Te Po Lo ool of 16 2 ja Jo 20 20 30 so o juo a0 ao GEOG OBO Ge Soc ee re fete fe I fe fo _ Page 98 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A APPENDIX C WINTERIZATION PROCCESS WARNING Not winterizing the Aqua Hot when freezing temperatures are present will result in serious damage to the Aqua Hot s Domestic Water Heating System Also be sure to use an FDA approved GRAS rated antifreeze for winterization NOTE The Aqua Hot can continue to be used for interior zone heating once the domestic water heating system has been drained and winterized The Aqua Hot s Domestic Water Heating System must be completely drained of domestic water any time the heater 15 stored where freezing temperatures may be experienced Winterizing the Domestic Water Heating System Please follow these instructions when winterizing the Aqua Hot s Domes
48. SH HOME 1530 30H enb md iP CH UNV LSOWMBHI 7 INOZ ve VII HSH wazy lt gt 2 IVISOWeSHI 2 327 ele z oes ime JAN HSH SNY4 amp 3NOZ g bo ume RO 8 uz 2 ON 99 W HOUMS OV 12018 TV NIBIL HOLUMS X90 183J1NI O O 1VISOMWPBHI fio 01 WM LI HOLING 1vOT14 Q Bi 998 c T pe 9 at nig 25 1viSONWu3Hi o MOOSI 2vAOEI 1N3 313 Aaya Page 50 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A DIESEL BURNER SECTION 6 dung 215 16181 jur yH 16151 jur V ILI OS 16151 jur V ILI 0210 16151 III uBiH 0210 5910 rg 10151 104007 98 12151 04002 L punoJc 28 X20 8 esnJ pg 14617 201221 cg 14617 20 221 9g pee SV 0 jig 8 9T 8 SL IV LL DE Dl ig 8l pea l enig CI ule zl pey YATIOALNOS JINAN e CAD CELL 12 VDC B M H3MO 18 Page 51 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 7 DETACHING AND REATTACHING THE DIESEL BURNER Instructions for Detaching the Diesel Burner WARNING Be sure to move the Diesel Burner switch on the Interior Switch Panel to the OFF position and disconnect the Diesel Burner s power supply before detaching the Diesel Burner from the Aqua Hot Failure to turn of
49. SWITCH PANEL e Electric Burner Switch Switch WITCH Terminal Block AO in 1 Terminal Block DO Pin 2 Terminal Block A1 in 2 Terminal Block D1 Pin 4 Jump to Pin 1 Pin 4 Terminal Block L Pin 6 Chassis Ground Pin 6 Terminal Block L TERMINAL BLOCK AC SWITCH AC SWITCH II ZONE 2 FANS ZONE 1 FANS ZONE 2 THERMOSTAT ZONE 1 THERMOSTAT BURNER CONTROL SWITCH BURNER CONTROL SWITCH INDICATOR LIGHT INDICATOR LIGHT THERMOSTAT ZONE 2 PUMP QuO eO DQ EFQ OQ CC O20 CC FO eo 0 ELECTRIC BURNER Page 16 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 SECTION 3 EXHAUST SYSTEM REQUIREMENTS Because the Aqua Hot s exhaust is hot and must be kept e The exhaust must be able to freely exit away from the away from any heat sensitive material the exhaust system vehicle without any obstructions should be checked to ensure that it continues to meet the following requirements e Two inch standard automotive type exhaust piping should be used with a maximum of two 90 degree pipe e The exhaust must not be directed downward as a fire bends and should not exceed 20 feet could result when parked in dry grassy areas e 3 inch and 4 inch black pipe nipples and the ex e The exhaust must not terminate underneath the vehicle haust elbow originally supplied with the Aqua Hot underneath an openable window or vent in th
50. TION 9 SWITCH PANEL BLINKING FAULT INDICATOR LIGHT The Interior Switch Panel incorporates a self diagnostic Blink ing Fault Indicator Light which by using a series of blinking lights indicates the particular component of the Diesel Burner that failed during operation Should a Diesel Burner malfunction occur the Aqua Hot Hy dronic Heating System will cease operation and will activate the appropriate Indicator Light Blinking Fault Sequence Each series of blinks are active for 0 5 seconds ON and 0 5 seconds OFF with a three second interval between each fault series This sequence will repeat continuously until the Diesel Burner switch is moved to the OFF position the 12 Volt DC power is disconnected from the Diesel Burner s Controller or the access cover 1s removed from the Aqua Hot Once the Diesel Burner fault has been corrected the Switch Panel Blinking Fault Indicator Light will need to be manually reset by turning OFF the Diesel Burner switch for approxi mately 30 seconds then turning it back ON Diesel Burner Fault Codes NOTE If the fault codes are not corrected by the checks listed below each specific code contact the Aqua Hot Heating Systems Technical Support Department at 1 800 685 4298 Fault Code 0 Indicator light is not illuminated but the Diesel Burner Switch is ON 1 Isthe Access Cover installed 2 Isthe Interlock Switch s wiring connected 3 Does the Interlock Switch have continuity
51. a 3 8 inch socket wrench remove the two bolts se Replace the Air Shutter 1f it becomes bent or damaged curing the Fuel Pump Assembly to the Blower Housing Replacement Procedure 5 Pull the Fuel Pump Assembly straight out from the Blower Housing CAUT NM NOTE The Coupling may remain attached to the Fuel Pump Be sure to clamp off the Fuel Supply and Return lines prior to Assembly upon removal from the Diesel Burner beginning this replacement procedure Page 76 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 8 DIESEL BURNER COMPONENTS AND REPAIR INFORMATION 6 Using a 5 16 inch socket wrench loosen and remove the bolt securing the Air Shutter to the Blower Housing 7 Remove the damaged Air Shutter from the Diesel Burner 8 Install the replacement Air Shutter on the Diesel Burner and secure with the bolt previously removed NOTE Be sure the Combustion Air Indicator on the Air Shut ter falls correctly on the Blower Housing s Combus tion Air Adjustment Scale once installed 9 Insert the Fuel Pump Assembly and attached Coupling if applicable into the Blower Housing NOTE In order to connect the Fuel Pump Assembly to the Blower Motor with the Coupling it may be necessary to pull the Ignition Module Assembly back on its hinge and rotate the Blower Wheel slowly until both the Blower Motor and the Fuel Pump Assembly are seated correctly on the Coupling 10
52. acing the control thermostat Troubleshooting 3 If the Electric Element does come and run but there 19 still a lack of domestic hot water interior coach heat 1 Turn the electric element switch on from the interior switch panel and ensure that the boiler tank has suffi ciently cooled in order to require heat from the electric element 1 Check operational temperature of the control thermostat by using a digital thermometer 2 Using a Clamp on Amp meter put it around the Black wire 51 coming off of the electric element Set the Note The operational range of the Electric Element con trol thermostat 1s 158 F 190 F Clamp on Amp meter to register AC amps The 1500 Watt electric element should pull 11 5 12 5amps If the temperature range of the control thermostat is NOTE The coach must either be plugged into shore not within specifications replace the control power or the generator must be on for there to be thermostat Figure 11 120vac at the heater 185 F Control Thermostat Please note that the Diesel Burner has been removed in this image Page 22 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 SECTION 4 AQUA HoT COMPONENTS Thermostats continued Control Thermostat Electric Element continued Replacement Procedure 1 Ensure that the Aqua Hot has been completely 5 Install the replacement control thermostat tightening only t
53. all the Flame Tube Spacer E Securely Tighten the four 5 16 24 nuts Previously removed y gt SPE AS 3 n 2i f avs be gt L L t LE d t ee eu 4 Zn p a PN ELE P 4 7 i 4 DEL uA X Rr d M MI rv SY d 1 M lt gt 4 Y SN t A i TX gt pr gt n f i LS 4 gt 7 gt 4 gt 4 gt P T m z v vw LL E L t 4 e J A 4 o Pj pc gt NV LJ e LI am om Flame Tube Flame Tube Flame Tube Spacer Gasket 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A Page 106 APPENDIX E ANNUAL MAINTENANCE PROCEDURE 4 Reinstall The Diesel Burner TONE Figure 98 Install New Gasket for Diesel Burner and install B Tighten Bolts Securing Diesel Burner to Heater the Diesel burner C Tighten Fuel fittings A Plug in the Diesel Burner Controller NOTE After connecting Fuel lines going to Diesel Burner it is recommended to remove pinch off pliers previously used on the fuel lines coming into the heater Page 107 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 APPENDIX E ANNUAL MAINTENANCE PROCEDURE Step 5 Replace the Fuel Nozzle NOTE The Diese
54. ange between 115 F 123 F If the proper range cannot be set follow the instructions in this section to replace the tempering valve If the tempering valve s knob does not turn freely fol low the instructions in this section to replace the temper ing valve Replacement Procedure A DANGER A FAILURE TO DISCONNECT ALL POWER SUPPLIES AND OR TO ALLOW THE HEATER TO COOL BEFORE SERVICING COULD CAUSE SERIOUS DAMAGE OR PERSONAL INJURY 1 Turn the motorhome s water pump off 2 Drain the water pressure by opening the faucets and al lowing the water to drain 3 Disconnect the motorhome s water lines from the tem pering valve assembly 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 4 AQUA HOT COMPONENTS 4 Disconnect the pex pipe and fittings from the tempering valve assembly 5 Remove the pressure relief valve assembly from the tempering valve assembly as the tempering valve cannot be removed from the Aqua Hot with the pressure relief valve still attached 6 Using a back up wrench unscrew the tempering valve from the Aqua Hot CAUTION A back up wrench must be used for loosening and removing the tempering valve from the Aqua Hot Failure to use the back up wrench will cause the copper domestic water coil to twist and kink which will render the domestic water feature unusable 7 Remove the brass fittings from the defective tempering valve 8 Install th
55. are not operating When each particular zone s room thermostat 1s turned on does the corresponding relay activate Is the Low Temp Cutoff Thermostat tripped A Unhook Thermostat Wires and using a volt meter check thermostat for continuity Check for power at the relay for the fans Pin 8 Check the heat exchanger for loose wires Using a voltmeter check for 12 Volts at the malfunctioning fan If applicable 15 the switch for the fan on The Aqua Hot is operating but the domestic hot water system is not producing hot water Reference Section 1 pages 13 14 and ensure that the Aqua Hot is using the appropriate antifreeze type and mixture ratio Verify that the water outlet s domestic hot water flow rate 1s at or below 1 5 Gallons per Minute GPM Verify that the outside water faucet is turned off Is the diesel burner operating Verify that the tempering valve is properly adjusted Temperature of water coming out of hot water faucet should be between 115 F 123 F Ensure that the Low Temp Cut Off Thermostat is operating properly Ensure that the Boiler Tank s Stir Pump is operating Check Temperature of the cold water coming in Make sure the heater has not been bypassed Page 95 O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A E SECTION 10 TROUBLE SHOOTING The Electric Element switch has been turned on however the Aqua Hot s 120 volt ac electric heating element does not operate i e lack
56. ary to rotate the Coupling slowly to properly seat it on the Fuel Pump Assembly s shaft servicing Failure to do so could result in serious personal injury electrical shock or even death once the Coupling is seated properly the Coupling will slide straight back onto the Fuel Pump Assem bly s shaft Function The Coupling creates a bridge between the Blower Motor and 5 Insert the Blower Motor and Blower Wheel Assembly into Fuel Pump Assembly Through the Coupling the Fuel Pump the Blower Housing and secure it with the two bolts previ Assembly is activated to pressurize the diesel fuel whenever ously removed Combustion Air is being created by the Blower Motor and Blower Wheel Assembly NOTE In order to connect the Fuel Pump Assembly to the Blower Motor with the Coupling it may be necessary to pull the Ignition Module Assembly back on its Replacement Indicator hinge and rotate the Blower Wheel slowly until both Replace the Coupling if it becomes broken cracked or is too the Blower Motor and the Fuel Pump Assembly are seated correctly on the Coupling worn to function properly 6 Following the procedure for Detaching and Reattaching Replacement Procedure CAUTION the Diesel Burner located in Section 7 of this manual reattach the Diesel Burner to the Aqua Hot NOTE The Mounting Gasket must be replaced each time the Be sure to clamp off the Fuel Supply and Return lines prior t
57. ater to be present the diesel burner must be selected also as a heating source 1 Verify that the motorhome is either plugged into shore power or that the generator 1s running to provide AC power 2 Verify that the Electric Switch is on inside the motor home 3 Using a Volt Meter Verify the presence of 12vdc volt age at the terminal block on both the AI power in from switch and AO power out to switch pins If there is no 12VDC voltage present complete the fol lowing A Verify that the electric element switch on the interi or switch panel is on B Verify heater 15 full of antifreeze if the heater 15 full of antifreeze trouble shoot Float Switch C Install a jumper wire on the terminal block between the AI and AO pins to bypass the electric element switch If the Electric Heating Element works with the jumper wire installed replace switch O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 4 AQUA HOT COMPONENTS If the Electric Switch 1s on and operating properly A Check the temperature of the Aqua Hot s boiler tank If the boiler tank temperature is below 158 F trou bleshoot the control thermostat for the electric ele ment If the boiler tank is above 185 F the Aqua Hot is at operating temperature and requires no heat Check functionality of the A C Relay Refer to A C Relay troubleshooting in this section Verify that the electric heating
58. attach the Fuel Supply Tube Assembly to the Escutch 10 Following the procedure for Detaching and Reattaching eon Plate Fuel Connection and Fuel Pump Assembly and the Diesel Burner located in Section 7 of this manual tighten both hexagonal locknuts with a 7 16 inch open end reattach the Diesel Burner to the Aqua Hot wrench CAUTION Be sure to remove the clamps from the Fuel Supply and Fuel Return lines prior to starting the Diesel Burner Failure to do so could result in serious damage to the Diesel Burner Short piece of hose connected to the Aqua Hot s fuel Inlet port Figure 71 INING IM Container of Diesel fuel the fuel SAqua Hot Pump Assembly will draw from ee MNT Rt mnm tati e cte m Short piece of hose connected to the Aqua Hot s fuel outlet port D Container for return of Diesel fuel Y gt M Fuel Pump Assembly Component Test ___ sew Fuel Pump Assembly s Fuel Solenoid Valve Fuel Pump Fuel Supply Assembly Tube Assembly LI N Y Figure 72 Assembly 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 8 DiESEL BURNER COMPONENTS AND REPAIR INFORMATION Cord Set 1 Unplug the Cord Set from the Fuel Pump Assembly s Fuel Solenoid Valve 2 Remove the Cord Set s white and violet wires from the 7 A DAWN G E R A and 8 terminals on the Diesel Burner s white electrica
59. cement Escutcheon Plate Spline Nut on the Igniter Assembly and tighten completely NOTE Verify that the Escutcheon Plate is adjusted to the edge of the label affixed to the Blower Housing 6 Reattach the Fuel Supply Tube to the Igniter Assembly and tighten the hexagonal locknut 7 Tighten the Fuel Supply Tube Assembly s hexagonal lock nut to the Fuel Pump Assembly Escutcheon Plate Spline Nut Page 80 O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 8 DIESEL BURNER COMPONENTS AND REPAIR INFORMATION Escutcheon Plate 2 Using a 7 16 inch open end wrench remove the Fuel supply Tube Assembly s hexagonal locknut which se cures the Fuel Supply Tube to the Igniter Assembly A DANGER A The Aqua Hot operates on both AC and DC power Be 3 Remove the Fuel Supply Tube from the Igniter Assembly sure to disconnect the 120 Volt AC power supply prior to and rotate out of the way servicing Failure to do so could result in serious personal injury electrical shock or even death 4 Using a 3 4 inch open end wrench remove the Escutcheon 9 9 Plate Spline Nut from the Diesel Burner s Escutcheon Plate Fuel Connection Function The Escutcheon Plate assists with the proper placement of the ng OI SORE Igniter Assembly when tightened and can also be loosened to ease the removal of the Igniter Assembly 6 Rem
60. ck the Aqua Hot s antifreeze and water heating solution to ensure that it 1s filled to the proper level This solution level should be checked in the Aqua Hot s Expansion Tank and should only be checked when the Aqua Hot is at maximum operating temperature 1 e when the Diesel Burner cycles OFF at 190 5 F The antifreeze and water heating solution s level should be at the HOT mark on the Expansion Tank reference Figure 30 If the antifreeze and water heating solution needs replenishing fill the Aqua Hot s Expansion Tank to the HOT level mark Be sure to reference Section 1 Antifreeze and Water Heating Solution for the proper antifreeze type and mixture If the antifreeze and water heating solution frequently needs replen ishing please contact the Aqua Hot Heating Systems Tech nical Department at 1 800 685 4298 for assistance Annually A DANGER A The Aqua Hot operates on both AC and DC power Be sure to disconnect the 120 Volt AC power supply prior to cleaning or servicing Failure to do so could result in serious personal injury electrical shock or even death WARNING Operating the Aqua Hot s Diesel Burner or the 120 Volt AC Electric Heating Element without the antifreeze and water heating solution will cause serious damage to the heater To keep the Aqua Hot running smoothly it 15 ideal to have the Diesel Burner tuned up annually A tune up should consist of a new Fuel Nozzle and Fuel Filter along wit
61. d Fuel Nozzle and Fuel Filter 1 e 10 Micron when replacing these parts NOTE The Diesel Burner does not need to be detached from the Aqua Hot in order to replace the fuel nozzle The Aqua Hot operates on both AC and DC power Be sure to disconnect the 120 Volt AC power supply prior to cleaning or servicing Failure to do so could result in serious personal injury electrical shock or even death WARNING Operating the Aqua Hot s Diesel Burner or the 120 Volt AC Electric Heating Element without the antifreeze and water heating solution will cause serious damage to the heater NOTE Be sure to use care when handling the Fuel Nozzle oils and or small dust or dirt particles from the hands may plug the nozzle s small orifice A par tially plugged orifice will restrict fuel flow which will affect the combustion process of the Diesel Burner e g excessive smoking etc O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A Fuel Filter 10 Micron 4 amp Fuel Nozzle 0 35 GPH lt Combustion Chamber Page 102 Step 3 Run the Diesel Burner Note Before performing an annual maintenance it is recommended to test run the Diesel Burner While testing inspect 1 Turn the Diesel Burner Switch to the on po exhaust for smoke sition 2 After the Diesel Burner has ignited let it burn for 2 minutes to purge the old fuel Step 1 Test Run the Diesel Burne
62. e boiling and rust anti corrosive protection A 50 50 mixture ratio 1s recommended which will result in a freeze point of approximately 28 F and a boil point of approxi mately 222 F The following information should be utilized for the purpose of clarifying some terms commonly associated with anti freeze Page 13 SECTION 1 INTRODUCTION TO THE AQUA HorT 375D Freeze Point and Burst Point Antifreeze lowers the freezing point of any liquid to which it has been added by preventing the formation of ice crystals however as the ambient temperature continues to decline the water in the solution will attempt to attain a solid state The point in which the water begins to solidify is termed the Freeze Point Although the water in the solution has be gun to freeze producing a slushy consistency the anti freeze in the solution will continue to combat the normal expansion of the solution as it freezes The point in which the solution can begin to expand due to colder temperatures is called the burst point Once the solution reaches the burst point the potential 1s present for ruptured pipes to ex ist The burst point of the antifreeze and water heating solu tion is dependent upon the brand of propylene glycol em ployed Boiling Point The Aqua Hot utilizes the antifreeze and water heating solu tion as a transportation means for the heat produced from the internal processes The antifreeze absorbs the hea
63. e AC high limit thermostat if the following condition has occurred e The electric heating element fails to operate Troubleshooting 1 Disconnect all power supplies 2 Verify that the boiler tank s temperature is below 215 F 3 Locate the AC high limit thermostat and remove its wires Reference Figure 13 for location 4 Using an ohmmeter check the thermostat for continuity If there is no continuity press the white reset button on the thermostat and re check for continuity If continuity 1s still not present after the reset button has been pressed follow the instructions in this section to replace the AC high limit thermostat Figure 13 215 Reset Button 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 4 AQUA HOT COMPONENTS Replacement Procedure A DANGER FAILURE TO DISCONNECT ALL POWER SUPPLIES AND OR TO ALLOW THE HEATER TO COOL BEFORE SERVICING COULD CAUSE SERIOUS DAMAGE OR PERSONAL INJURY 1 Ensure that the Aqua Hot has been completely shut down and that all power supplies have been disconnect ed 2 If applicable remove the heat shrink insulation covering the wires and terminals on the defective high limit ther mostat 3 Remove the two wires from the defective high limit thermostat by pulling firmly on the wires 4 Using a 5 8 wrench or socket remove the defective high limit thermostat from the Aqua Hot s boiler tank 5 Install t
64. e awning must be present area of the motorhome if applicable or near slide out areas e The exhaust should be inspected for excessive bends excessive length kinks or any type of restriction e A maximum of one 90 and one 45 exhaust pipe bends are allowed e The total length of the exhaust pipe shall not exceed 11 2Aqua Hat ICI CC I Cates 175 Dapth of Motorhame Bay Floor Exhaust Pipe Mounting Tray Flange 3 inch Nipple Page 17 O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A E This section details various components of the Aqua Hot that may require troubleshooting and or replacement in the event of a malfunction The diesel burner and its components are detailed in Section 8 of this manual Replacement parts can be ordered through Aqua Hot s Web site at www aquahot com or by calling 1 800 685 4298 If additional assistance is needed the Technical Support Team can also be reached Monday through Friday from 7 00 AM to 4 00 PM Mountain Standard Time at 1 800 685 4298 Sensors Switches Interlock Switch The interlock switch is a safety device designed to ensure that the Aqua Hot s access cover is securely installed before allowing the diesel burner to operate Note If the cover is removed or the interlock switch is de fective the diesel burner switch indicator light will not illu minate Troubleshoot the interlock switch if the
65. e brass fittings onto the replacement tempering valve 9 Install the replacement tempering valve onto the Aqua Hot using a back up wrench to tighten 10 Install the pressure relief valve onto the replacement tempering valve 11 Reconnect the pex pipe and fittings to the tempering valve and Aqua Hot 12 Reconnect the motorhome s water lines to the tempering valve assembly ensuring they are plumbed correctly 13 Turn the motorhome s water pump back on and check for leaks and the presence of hot domestic water 14 Verify that the replacement tempering valve has been set to the proper setting by taking a digital thermometer to a hot water faucet and set the water temperature between 1 15 F 123 F Page 30 Figure 18 Pumps Zone Pumps 1 and 2 The Zone pumps first draw the heated antifreeze and water heating solution from the Aqua Hot s boiler tank then pro pel it through the hydronic heating system s interior heat plumbing Troubleshoot the Zone pumps 1f the following condition has occurred e Zone pump is not operating e There is a lack of heat in the coach Troubleshooting NOTE Reference wiring Schematic in Appendix A 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 4 AQUA HOT COMPONENTS 1 Turn on the interior room thermostat corresponding to the Zone pump not operating A Using a Volt Meter Check for voltage on the Fuse
66. e care when handling the replacement Fuel Nozzle as oils and or small dust particles from the hands may plug the Fuel Nozzle s small orifice A partially plugged orifice will restrict fuel flow which will affect the combustion process of the Die sel Burner 1 e excessive smoking 1 Loosen the Fuel Supply Tube Assembly s hexagonal locknut on the Fuel Pump Assembly with a 7 16 inch open end wrench NOTE The Fuel Supply Tube Assembly does not need to be completely removed from the Fuel Pump Assem bly but must be loosened to rotate out of the way Page 62 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 8 DIESEL BURNER COMPONENTS AND REPAIR INFORMATION Using a 7 16 inch open end wrench remove the Fuel supply Tube Assembly s hexagonal locknut which se cures the Fuel Supply Tube to the Igniter Assembly Remove the Fuel Supply Tube Assembly from the Igniter Assembly and rotate out of the way Loosen the two screws securing the Ignition Module Re taining Clips and rotate both clips to release the Ignition Module Then tilt the Ignition Module back on its hinge Loosen and remove the Escutcheon Plate Spline Nut from the Escutcheon Plate Reach into the Blower Housing and pull the Igniter As sembly out of the Diesel Burner being careful not to dam age the electrodes or insulators while handling NOTE To ease the removal of the Igniter Assembly rotate the Igniter
67. e motorhome s bay floor prior to beginning this antifreeze and water heating solution fill procedure Failure to do so could result in an antifreeze spill in the motorhome s bay Reference Figure 30 In order to provide the best freeze protection boil over pro tection and anti corrosion and rust protection a 50 50 mix ture of GRAS approved propylene glycol boiler antifreeze and water is recommended Reference Section 1 Antifreeze and Water Heating Solution for additional information regarding the antifreeze and water heating solution Be sure to use a GRAS boiler type pro pylene glycol based antifreeze rather than an RV and Marine antifreeze or an automotive antifreeze coolant If assistance is needed in selecting an appropriate antifreeze please contact the Aqua Hot Heating Systems Product Appli 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A cation Department at 1 800 685 4298 TO DRAIN THE AQUA HOT 1 Connect a piece of 1 2 inch PEX type tubing or rubber hose to the drain valve This piece should be long enough to transport the antifreeze and water heating solution from the Aqua hot to a bucket 2 Open the Aqua Hot s drain valve located at the front of the heater Reference Figure 27 Note The Aqua Hot 375 holds approximate ly 5 gallons of the antifreeze and water heating solution Figure 28 Page 42 General Recommended Maintenance Monthly Che
68. e the Low Temperature cut off Thermostat 15 not tripped by Making sure the heater 1s up to operating temperature and that domestic hot water 1s not being used Reference Low Temperature Cut off thermostat troubleshooting in this section Figure 23 7 Lal o 4 SN OTE ver Tes vsa ri teciarer pioijunag 16304 Page 38 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 SECTION 5 FILLING THE AQUA HOT WITH HEATING SOLUTION WARNING Only propylene glycol based boiler type antifreeze deemed GRAS Generally Recognized as Safe by the FDA shall be used in the Aqua Hot s hydronic heating system Failure to use the above specified antifreeze type could result in serious injury or death Ensure that the overflow tube is connected from the Aqua Hot s expansion tank connection to the expansion tank s bottom connection and from the expansion tank s top con nection through the overflow tube hole in the motorhome s bay floor prior to beginning this antifreeze and water heating solution fill procedure Failure to do so could result in an antifreeze spill in the motorhome s bay Reference Figure 30 Figure 24 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A Air Release Valve Expansion Tank Connection Purging the Hydronic Heating System In order to provide the best freeze p
69. eaks or fails to pump fuel Component Test 1 Clamp off the Fuel Supply and Return lines at the ports on top of the Aqua Hot then remove these lines completely 2 Attach short pieces of fuel line to both the Aqua Hot s Fuel Return and Fuel Supply ports reference Figure 31 3 Submerse the hose connected to the Fuel Supply port into a container of diesel fuel reference Figure 31 4 Placethe hose connected to the Fuel Return port into an empty container 5 Turn the Interior Switch Panel s Diesel Burner switch ON to activate the Diesel Burner NOTE If fuel does not flow into the empty container from the Aqua Hot s Fuel Return port and there are no air leaks in the fuel system the Fuel Pump Assembly must be replaced Fuel Pressure Check and Adjustment Procedure For information regarding a Fuel Pressure Test and or Adjust ment Procedure for the Diesel Burner please contact the Tech nical Support Department at 1 800 685 4298 Replacement Procedure CAUTION Be sure to clamp off the Fuel Supply and Return lines prior to beginning this replacement procedure 1 Following the procedure for Detaching and Reattaching the Diesel Burner located in Section 7 of this manual detach the Diesel Burner from the Aqua Hot 2 Unplug the Cord Set from the Fuel Pump Assembly s Fuel Solenoid Valve O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 8 DIESEL BURNER COMPO
70. element 15 receiving ade quate AC power by completing the following A Remove the AC access cover B Using an AC voltmeter verify that 110 volts of AC power are present C Using an amp meter verify that 11 2 to 13 amps are present at the element s wires D Disconnect the coach from shore power turn off generator and Check the electric element s wires for continuity by completing the following a Disconnect the wires from the electric heating element b Disconnect the wires from the AC terminal block c Check the black and white wires at the terminal block for continuity Check the electric heating element for functionality by completing the following A Disconnect all power supplies B Remove all wires from the electric heating element C Using an ohmmeter check the electric heating ele ment for continuity Page 34 If no continuity exists follow the instructions in this section to replace the electric heating element Replacement Procedure A DANGER A FAILURE TO DISCONNECT ALL POWER SUPPLIES AND OR TO ALLOW THE HEATER TO COOL BEFORE SERVICING COULD CAUSE SERIOUS DAMAGE OR PERSONAL INJURY 1 Ensure that the Aqua Hot has been completely shut down and that all power sources have been disconnect ed Also because this replacement procedure will in volve the boiler tank and the potential for hot coolant be sure the heater has adequately cooled 2 Drain the antifreeze and
71. emperatures exist and or when there is a low demand for domestic hot wa ter If the 120 Volt AC Electric Heating Element is not providing enough heat turn the Diesel Burner on in conjunction with the 120 Volt AC Electric Heating Element Figure 90 Diesel Burner 1 Ifthe Diesel burner Fails to operate A The Fuel level in the main diesel fuel tank is below 1 4 tank B When was the last time an Annual Service was performed C Is the Diesel Fuel liquid or Jelled D Are the electrodes properly adjusted E Is the Diesel Fuel in the motor home winter fuel or summer fuel In extreme cold weather it may be necessary to acti vate the 120 Volt A C Electric Heating Element for 1 2 hours prior to activating the burner to preheat the burner on the initial start up cycle only Aqua Hot xs OGYI ON Fiectric Element Diesel Burner Page 100 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A Front APPENDIX D EXTREME COLD WEATHER OPERATION If there is a lack of Interior Heat During Cold Weather Operation Note The 120 Volt AC Electric Heating Element is the Aqua Hot s secondary heat source for heating both the interior and or the domestic hot water during low heat ing demand situations such as when moderate ambient temperatures exist and or when there is a low demand for domestic hot water If the ambient temperature is ex tremely cold the
72. ene glycol based anti freeze 1s selected RV amp Marine Antifreeze These types of propylene glycol based antifreeze products are formulated specifically for winterizing applications only Although RV amp Marine antifreeze 15 often Generally Recognized as Safe by the FDA it should never be used in the Aqua Hot s Hydronic Heating System Boiler Tank This type of antifreeze is not formulated to transfer heat which is essential to the heating system s functionality and does not contain rust inhibitors Please note however that RV amp Marine antifreeze can be utilized to winterize the Aqua Hot s domestic water heating system Automotive Antifreeze Coolant These types of propylene glycol based antifreeze products are formulated specifically to protect automotive engines against corrosion freezing temperatures and overheating They also have excellent heat transfer and thermal conduc 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A tivity characteristics Although these types of antifreeze products are considered less toxic and safer than ethylene glycol for people pets and the environment they are not Generally Recognized as Safe GRAS rated by the FDA Therefore they must be marked with a harmful if swal lowed warning This additional warning is required be cause these types of antifreeze products contain high levels of chemical inhibitors Due to their potentially hazardous
73. ent are present at both the red positive wire and the yellow orange signal wire but no operational 2 Using a voltmeter insert the negative probe into the 74 terminal of the Diesel Burner s white electrical plug ref usc UI erence Figure 34 and Appendix A Blower Motor Replacement Procedure in this section of the manual Blower Motor Figure 83 Flat of the Blower ON Motor s shaft for the EN set screw P lt Insert Feeler Gauge between the Blower Wheel and the Access Hole Blower Motor to set screw Page 86 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 8 DIESEL BURNER COMPONENTS AND REPAIR INFORMATION NOTE If the Blower Motor s yellow orange signal wire does not reflect current when the Aqua Hot s Control Ther mostat 1s calling for heat the Diesel Burner Controller may need to be replaced Replacement Procedure CAUTION sure to clamp off the Fuel Supply and Return lines prior to beginning this replacement procedure 1 Following the procedure for Detaching and Reattaching the Diesel Burner located in Section 7 of this manual detach the Diesel Burner from the Aqua Hot 2 Using a Molex Pin Extractor tool remove the Blower Mo tor s three wires from the 3 4 and 9 terminals on the Diesel Burner s white electrical plug Reference Figure 34 3 Pull the Blower Motor s three wires back thro
74. er Be sure to disconnect the 120 Volt AC power supply prior to servicing Failure to do so could result in serious personal injury electrical shock or even death Function The Air Band in conjunction with the Air Shutter helps con trol the Diesel Burner s Combustion Air level which mixes with the diesel fuel spray and 1s ignited in order to establish a flame to heat the Aqua Hot s Boiler Tank Replacement Indicator Replace the Air Band if it becomes bent or damaged Replacement Procedure CAUTION Be sure to clamp off the Fuel Supply and Return lines prior to beginning this replacement procedure 1 Following the procedure for Detaching and Reattaching the Diesel Burner located in Section 7 of this manual detach the Diesel Burner from the Aqua Hot 2 Unplug the Cord Set from the Fuel Pump Assembly s Fuel Solenoid Valve 3 Remove the Fuel Supply Tube Assembly A Loosen both hexagonal locknuts on either end of the Fuel Supply Tube Assembly with a 7 16 inch open end wrench B Pull the Fuel Supply Tube Assembly away from the Blower Housing 4 Using a 3 8 inch socket wrench remove the two bolts se curing the Fuel Pump Assembly to the Blower Housing 5 Pull the Fuel Pump Assembly straight out from the Diesel Burner s Blower Housing O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A NOTE The Coupling may remain attached to the Fuel Pump Assembly upon removal fr
75. er switch is in the ON position A DANGER A The Aqua Hot operates on both AC and DC power Be sure to disconnect the 120 Volt AC power supply prior to as an electrical shock can occur NOTE Once the Diesel Burner switch 1s activated the volt meter should indicate 12 volts of current at the Blower servicing Failure to do so could result in serious personal injury electrical shock or even death Motor s positive wire Function 3 Using the same voltmeter insert the positive probe into The Blower Motor rotates the Blower Wheel which creates pa ii rina combustion air while also activating the Fuel Pump Assembly plug m aH d Spend which creates fuel pressure 7 4 Remove the voltmeter s positive probe from the 9 termi nal on the Diesel Burner s white electrical plug and rein Replacement Indicator l sert the probe into the 3 terminal to test the voltage at the Motor fails component test Blower Motor s Yellow Orange signal wire Twelve volts 5 Diesel Burner Switch Flashes fault code 2 of current should be present anytime the Aqua Hot calls for heat 5 Once it has been verified that 12 volts of current are pre Component Test sent at the Blower Motor s Yellow Orange signal wire Verify that the Interior Switch Panel s Diesel Burner and sounds antic Mowe Electric Element switches are in the OFF position 6 If 12 volts of curr
76. er tank s front plate 2 Install a new mounting gasket into place Figure 46 Figure 47 Step 2 Reinstall the Diesel Burner l T gt gt p _ gt 1 Align the Diesel Burner s front air tube plate with 2 Finger tighten all three nuts previously removed to the combustion chamber and slide onto the bolts secure the Diesel Burner to the boiler tank protruding from the boiler tank Figure 48 Figure 49 Page 56 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 SECTION 7 DETACHING AND REATTACHING THE DIESEL BURNER GS TT d f 3 Using a 9 16 socket wrench with a wobble extension tighten the three nuts securely Step 3 Reconnect the Fuel Lines a s 1 Connect the Supply and Return Fuel Lines to the 2 Using an 11 16 wrench tighten the nuts on the Diesel Burner s Fuel Pump Assembly fuel lines to the Fuel Pump Assembly to secure the lines in place Page 57 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 SECTION 7 DETACHING AND REATTACHING THE DIESEL BURNER Step 4 Reconnect the Diesel Burner to the Diesel Burner Controller Uf 7 gt 1 Push the Diesel Burner and Diesel Burner Con 2 Press down on the tabs to secure them together troller s connections together Page 58 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 SECTION 7 D
77. etaining Clips Secure the Fuel Supply Tube Assembly to the Diesel Burner and tighten both hexagonal locknuts completely NOTE Ensure that the Escutcheon Plate is set to the edge of 14 the indicator label on the Blower Housing Turn ON the Interior Switch Panel s Diesel Burner switch for 5 seconds then switch it OFF This will activate the Diesel Burner s prime cycle and flush the fuel system of any potential contaminants NOTE The Diesel Burner will fire anytime the Diesel Burner switch 19 turned on even if it is turned back off before the Diesel Burner actually fires Page 63 SECTION 8 DIESEL BURNER COMPONENTS AND REPAIR INFORMATION Igniter Assembly A DANGER A The Aqua Hot operates on both AC and DC power Be sure to disconnect the 120 Volt AC power supply prior to servicing Failure to do so could result in serious personal injury electrical shock or even death Function The Igniter Assembly contains the Ignition Electrodes Fuel Nozzle Static Plate and Fuel Supply Tube which together ignite the incoming fuel in order to create the Diesel Burner s flame Replacement Indicator Replace the Igniter Assembly if the Nozzle Holder 1s damaged or fuel pipe connection is damaged Replacement Procedure NOTE The Diesel Burner does not need to be detached from the Aqua Hot for this replacement procedure 1 Loosen the hexagonal locknut securing the Fuel Supply Tube
78. f the Diesel Burner and disconnect power could result in serious bodily injury CAUTION Be sure to clamp off the Fuel Supply and Return lines at the ports on top of the Aqua Hot prior to beginning this replacement procedure Step 1 Turn Off the Diesel Switch Aqua Hot Figure 37 HU ND PCM ON zd sie iar Element 1 Move the Interior Switch Panel s Diesel Burner switch to the OFF position Step 2 Remove the Access Cover Figure 38 M 7 1 Remove the Aqua Hot s access cover by locating 2 Unscrew the bolt securing the front of the cover in the bolts securing it in place place Page 52 O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A E SECTION 7 DETACHING AND REATTACHING THE DIESEL BURNER HYDRONIC HEATING SYSTEM qua Hot 3 Unscrew the bolt securing the top of the cover in 4 Lift the access cover off and set it aside place Figure 39 Figure 39A Step 3 Disconnect the Diesel Burner fro the Diesel Burner Controller 4 s EN f 1 8 t Locate the Diesel Burner s white electrical plug 2 Press back on the two tabs securing the connection to the Diesel Burner Controller connections together Figure 40 Figure 40A Page 53 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 SECTION 7 DETACHING AND REATTACHING THE DIESEL BURNER
79. f the temperature range of the control thermostat is not within specifications replace the control ther mostat Page 20 SECTION 4 AQUA HoT COMPONENTS Replacement Procedure 4 Using a 7 8 socket unscrew the control thermostat from A DANGER A FAILURE TO DISCONNECT ALL POWER SUPLIES AND OR TO the Aqua Hot s boiler tank 5 Wrap the threads of the replacement control thermostat with Teflon tape ALLOW THE HEATER TO COOL BEFORE SERVICING COULD CAUSE SERIOUS DAMAGE OR PERSONAL INJURY 6 Screw the replacement control thermostat into the port on the Aqua Hot boiler tank and tighten securely with a 1 Ensure that the Aqua Hot has been completely shut down 7 8 socket and that all power sources have been disconnected Also because this replacement procedure will involve the boiler 7 Reconnect control thermostat wires tank and the potential for hot coolant be sure the heater has adequately cooled 8 Refill the Aqua Hot boiler tank with the antifreeze and water heating solution 2 Drain 2 gallons of the antifreeze and water heating solu tion from the Aqua Hot boiler tank using the drain valve 9 Test the Aqua Hot for normal operation using a digital thermometer 3 Disconnect the defective control thermostat s wires by separating the quick disconnect terminals Reference Fig ure 10 for location Figure 10 Please note that the Diesel Burner has been removed in this image Page 21 2
80. following condition has occurred e The diesel burner fails to operate e The light on the diesel burner switch fails to illumi nate Troubleshooting NOTE The interlock switch will prevent the diesel burner from operating without the access cover intact therefore the switch will need to be manually oressed during testing for the switch s functionality 1 Turn the diesel burner switch on from the interior switch panel and ensure that the boiler tank has sufficiently cooled in order to require heat from the diesel burner 2 Disconnect the yellow and white wires from the inter lock switch noting that wire 31 is connected to the ter minal labeled NO and wire 9 15 connected to the ter minal labeled COM 3 Using an ohmmeter check the interlock switch for conti nuity while the button is pushed in 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 4 AQUA HOT COMPONENTS If continuity 1s not present with the button pushed in follow the instructions in this section to replace the interlock switch Replacement Procedure A DANGER A FAILURE TO DISCONNECT ALL POWER SUPPLIES AND OR TO ALLOW THE HEATER TO COOL BEFORE SERVICING COULD CAUSE SERIOUS DAMAGE OR PERSONAL INJURY 1 Disconnect the interlock switch s wires by pulling the quick connectors from the switch s spade terminals 2 Release the interlock switch from the Aqua Hot cabinet by pushing in on
81. for proper operation ing Clips and rotate both clips to release the Ignition Module a e Assembly then tilt the Ignition Module Assembly back on E itd 7 gt E AN 5 thf 4 p UR RS Ei gt Af D An P gt we 4 2 wee LP ce rig a y ee td S LR T 2 Ay s g lc m e t Pi A 77 T fr MUS VN Te SD 4 gt tS 7 fe E gt Aul TIU d fU 4 n Retaining Clips Diesel Burner s White Electrical Plug Page 67 O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 L yu Gasket Kit A DANGER A The Aqua Hot operates on both AC and DC power Be sure to disconnect the 120 Volt AC power supply prior to servicing Failure to do so could result in serious personal injury electrical shock or even death Function These Gaskets provide a tight seal between the Ignition Module and the Diesel Burner as well as protection for the Flame Sen sor Replacement Indicator The sealing surfaces of each Gasket should be checked and replaced at the first sign of any damage or deterioration 2 The Heater black smokes or rumbles Ignition Module Gasket Replacement Procedure NOTE The Diesel Burner does not need
82. free from the clip on the Ignition Module Assembly 3 Remove the defective Flame Sensor Gasket from the Flame Sensor Socket and slide the replacement Flame Sen sor Gasket onto the Flame Sensor Socket ensuring that the flat bottom of the Flame Sensor Gasket is level with the Flame Sensor s Mounting Bracket 4 Set the Flame Sensor Socket back into place by tilting the Flame Sensor Socket up at an angle to slide under the clip then set the Flame Sensor Socket and Mounting Bracket flat against the Ignition Module Assembly 5 Secure the Flame Sensor Socket into place by gently press ing down on the rear of the Flame Sensor Socket and push ing back toward the clip while wiggling the Flame Sensor Socket slightly until the Flame Sensor Socket moves into place 6 Place the Flame Sensor Gasket onto the tabs on the under side of the Ignition Module Assembly 7 Close the Ignition Module and secure with the Ignition Module Retaining Clips Ignition Module Retaining Clips Ignition Module Assembly Figure 66 Mounting Bracket Page 68 SECTION 8 DIESEL BURNER COMPONENTS AND REPAIR INFORMATION Bottom View of Ignition Module Assembly Igniter Springs Flame Sensor Flame Sensor Gasket Flame Sensor Socket Clip on Ignition Module Assembly to secure the Flame Sensor in place Figure 67 Screws which secure the Ignition Module Assembly to the Blower Housing Flame Sensor Flame Sensor Socket Ign
83. ge 19 Diesel Burner Control Page 20 21 Electric Element Control Thertriostal ue oe titu e o ea nemus Ee UU Page 22 23 Electric Element High Limit Thermostat Page 24 Diesel Burner High Limit Thermostat Page 25 Diesel Burner High Limit Thermostat Right cccceccsecceeeceeeseeeseeeseeeeeeseeeseeeseeenes Page 26 Low Temperature Cutoff Thermostat ccccccccsecceccceeceeseeesaseceeceeceuecaeeseeesaeeseeeaes Page 27 28 Interior Heating Zone Check Page 28 29 Domestic Water Tempering Valve cccccecceccseeceeceeceeceeeceeseeceecuesaeeseesaeeceesensaeesass Page 30 31 Interior Heating Zone Circulation Pumps 1 amp 2 Page 31 32 Fe CIMA CIS ACV urb Page 33 21 34 35 Electric Heating Element A C Relay Page 36 37 Interior iealing Zorne Relday Page 38 Section 5 Filling Draining The Aqua Hot 375D With Heating Solution FIMO THE AGUAHFIOU RTT UE TU TUTTI TM Page 39 41 DanH TNC AGUA E Page 42 O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A Table of Content
84. h a thorough cleaning of the Combustion Chamber if necessary reference Figure 29 To ensure maximum Diesel Burner performance always use the recommended Fuel Nozzle and Fuel Filter 1 e 10 Micron when replacing these parts NOTE Be sure to use care when handling the Fuel Nozzle oils and or small dust or dirt particles from the hands may plug the nozzle s small orifice A par tially plugged orifice will restrict fuel flow which will affect the combustion process of the Diesel Burner e g excessive smoking etc ECTION 6 DIESEL BURNER Fuel Filter 10 Micron lt Fuel Nozzle 0 35 GPH lt Combustion Chamber ST The antifreeze and water heating solution should be filled to the HOT level on the Expansion Tank when the Aqua Hot is at the maximum operating temperature Page 43 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 6 DiESEL BURNER Igniter Assembly A C Fuel Nozzle Electrode Static Plate Burner Mounting Ignition Plate Module Blower Housing Fuel Solenoid Combustion Air Fuel Supply Adjustment Scale Tube Flame Sensor and Flame Sensor Socket internal component Fuel Pump Assembly Fuel Pump Return Figure 31B Fuel Pump Supply Figure 31C Blower Wheel internal component Page 44 2009 Aqua Hot 375D Hydronic Heating Sy
85. he exhaust due to a control thermostat short cycling Troubleshooting 1 Turn the diesel burner switch on from the interior switch panel and ensure that the boiler tank has sufficiently cooled in order to require heat from the diesel burner If the burner does not come on and run check the fol lowing A Verify that the temperature of the boiler tank has fallen below the 158 F minimum operating temper ature by checking with a digital thermometer 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 4 AQUA HoT COMPONENTS NETS 5 amp 5 P d gt ja de ee ee eee v uam GES uS GED GS UND UNDA USB 9 Disconnect the control thermostat s wires from their connections and using an ohmmeter check for continuity If there is no continuity follow the instructions in this section for replacing the control thermostat If continuity exists complete the following 1 Inspect the control thermostat s wiring and connections for any signs of damage or corr osion If the diesel burner does come and run but there is still a lack of domestic hot water interior coach heat 1 Check operational temperature of the control thermostat by using a digital thermometer Note The operational range of the diesel burner control thermostat is 158 F 190 F I
86. he replacement high limit thermostat into the port on the Aqua Hot s boiler tank and finger tighten only 15 in Ibs 6 Connect the wires removed from the defective high limit thermostat to the replacement high limit thermostat 7 Test for normal operation Please note that the Diesel Burner has been removed in this image Page 24 DC High Limit Thermostat Left The left DC high limit thermostat serve as a safety measure in the event that the diesel burner continues to operate after the maximum operating temperature 1s reached The high limit thermostats allow the current for the diesel burner to pass through them until the boiler tank reaches a temperature of 215 F Should this temperature be reached the left high limit thermostat blocks the current to the diesel burner s controller which prevents the diesel burner from operating Troubleshoot the Left DC high limit thermostat if the follow ing condition has occurred e The diesel burner fails to operate e The diesel burner switch light flashes a 6 fault code Troubleshooting 1 Place a jumper wire between the black 15 and black 16 wires on the diesel burner s wire harness to by pass the high limit thermostats Check the Aqua Hot for normal operation NOTE Bypassing the high limit thermostats is for testing only and must not be used for the Aqua Hot normal operation 2 Disconnect the Left DC high limit thermostats wires then us
87. heck the Diesel Burner s Combustion Chamber for build up Check the exhaust pipe for damage or air flow restrictions Check the Diesel Burner s Flame Sensor to ensure that the lens is clean and for proper functionality Verify that the Combustion Air is set to the proper level Check that the Diesel Burner s gaskets are properly seated and not creating an obstruction Check that the Diesel Burner 1s firmly attached to the Aqua Hot Ensure that the Diesel Burner s gaskets are not worn or damaged HHO OO gt Check Diesel Burner s Blower motor for proper RPM 3600rpm Page 94 O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A E DoD D ae od SAN ee he SECTION 10 TROUBLE SHOOTING The Aqua Hot is operating but an interior and or fresh water tank heating zone is not working Is the Low Temp Cutoff Thermostat Tripped A Unhook Thermostat Wires and using a volt meter check thermostat for continuity Verify that the heat exchangers in that zone are working Check for loose wires Ensure that the check valve is not stuck in a closed position While the circulation pump 15 running place hand on lines to check for the presence of hot antifreeze and water heating solution Is the Zone Relay functioning properly Is the Room Thermostat signaling the Aqua Hot heater The Aqua Hot is at operating temperature however the interior and or fresh water tank heat exchanger fans
88. ing A Press the white reset button on the high limit ther mostat then re check for continuity 2 rx TSN E UN e lt gt p J t E t a 7 b 1 c 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 4 AQUA HoT COMPONENTS NOTE If a thermostat with the wires removed that has been reset does not have continuity follow the instructions in this section to replace the high limit thermostat B Disconnect the wires from the thermostat and re check the thermostat for continuity as well as the thermostats individual wires If an individual wire does not have continuity that wire must be replaced Replacement Procedure A DANGER A FAILURE TO DISCONNECT ALL POWER SUPPLIES AND OR TO ALLOW THE HEATER TO COOL BEFORE SERVICING COULD CAUSE SERIOUS DAMAGE OR PERSONAL INJURY 1 Ensure that the Aqua Hot has been completely shut down and that all power sources have been disconnect ed 2 Remove the two wires from the defective high limit thermostat by pulling firmly on the wires 3 Using a 5 8 wrench or socket remove the defective high limit thermostat from the Aqua Hot s boiler tank 4 Install the replacement high limit thermostat into the port on the Aqua Hot s boiler tank and finger tighten only 15 in Ibs 5 Connect the wires removed from the
89. ing an ohmmeter check the thermostat for conti nuity If there is no continuity complete the following A Press the white reset button on the high limit ther mostat then re check for continuity gt lt gt y _ gt V 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 4 AQUA HoT COMPONENTS NOTE If a thermostat with the wires removed that has been reset does not have continuity follow the instructions in this section to replace the high limit thermostat B Disconnect the wires from the thermostat and re check the thermostat for continuity as well as the thermostats individual wires If an individual wire does not have continuity that wire must be replaced Replacement Procedure A DANGER A FAILURE TO DISCONNECT ALL POWER SUPPLIES AND OR TO ALLOW THE HEATER TO COOL BEFORE SERVICING COULD CAUSE SERIOUS DAMAGE OR PERSONAL INJURY 1 Ensure that the Aqua Hot has been completely shut down and that all power sources have been disconnect ed 2 Remove the two wires from the defective high limit thermostat by pulling firmly on the wires 3 Using a 5 8 wrench or socket remove the defective high limit thermostat from the Aqua Hot s boiler tank 4 Install the replacement high limit thermostat into the port on the Aqua Hot s boiler tank and finger tighten only 15 in Ibs 5 Con
90. inished by hand tightening Look for the solution to enter the over flow tube attached to the expansion tank connection on top of the Aqua Hot 5 Close the drain valve Purging the System by Grounding the Zone Thermostat Connection 1 Ensure that the boiler tank has been filled with the ap propriate 50 50 mixture of antifreeze and water heating solution 2 Locate Terminal Block for switches heat exchangers fans and thermostats Reference Figure 26 3 Locate the thermostat connection terminals T1 and T2 Reference Figure 27 4 Connect a wire to the desired zone terminal and connect the opposite end of the cable to a ground source Refer ence Figure 27 NOTE The circulation pump will activate as soon as the terminal is connected to a ground source therefore disconnect the wire from the ground source during the antifreeze and water heating solution filling pro cedure 5 Allow the circulation pump to operate for approximately 1 3 minutes in order to purge the corresponding heating loop then remove the wire from the ground source 6 Open the drain valve and completely fill the Aqua Hot s boiler tank with additional antifreeze and water heating solution Page 40 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A T Repeat steps 5 and 6 for both heating loops until all air has been completely bled from the entire heating system NOTE All air is bled from the heating syste
91. iter Spring Flame Sensor Gasket Flame Sensor Gasket Tabs which hold the Flame Sensor Gasket in place Flame Sensor Mounting Bracket Clip on Ignition Module Assembly to secure the Flame Sensor Socket in place Figure 68 Side View of Ignition Module Assembly Page 69 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 8 DiESEL BURNER COMPONENTS AND REPAIR INFORMATION Flame Sensor and Flame Sensor Socket A DANGER A The Aqua Hot operates on both AC and DC power Be sure to disconnect the 120 Volt AC power supply prior to servic ing Failure to do so could result in serious personal injury electrical shock or even death NOTE Ensure that the ohmmeter has been calibrated prior to checking the Flame Sensor for resistance Function The Flame Sensor and Flame Sensor Socket together create a photo resistive device which supplies the Diesel Burner s Elec tronic Controller with a DC voltage signal when it detects a flame 1 e light source Replacement Indicator Cracked Component Test Fails Component Test 1 Remove the Flame Sensor from the Flame Sensor Socket 2 Using an ohmmeter test the Flame Sensor by covering the Flame Sensor s glass surface with a shop rag to simulate a no flame condition resistance should be greater than 20 000 ohms then expose the lens to a light source to sim ulate a flame condition resistance should be less than 1 600
92. l The Aqua Hot operates on both AC and DC power Be plug sure to disconnect the 120 Volt AC power supply prior to 3 Work the wires and Cord Set out and away from the Die servicing Failure to do so could result in serious personal injury electrical shock or even death iene NOTE It may be necessary to clip off and remove the wire Function ties bundling the Diesel Burner components wires together in order to free the Cord Set for removal The Cord Set provides a removable wiring network between the Fuel Solenoid and the Diesel Burner s white electrical plug 4 Insert the replacement Cord Set s wires into the Blower Housing through the Blower Housing Wiring Access Hole and insert the Cord Set s wires into the Diesel Replacement Indicator Burner s white electrical plug The violet wire should be Keplucedhe Cord or ludis damaged orna inserted into the 7 terminal and the white wire should be ae inserted into the 8 terminal on the Diesel Burner s white functioning electrical plug reference Figure 34 and Appendix A Replacement Procedure 5 Plug the opposite end of the Cord Set into the Fuel Sole NOTE The Diesel Burner does not need to be detached from noid Valve the Aqua Hot for this replacement procedure Blower Motor and Blower Wheel Figure 73 Assembly Fuel Supply Tube Assembly Plastic Air Fuel Pump Assembly Gud
93. l Burner does not need to be detached from the Aqua Hot in order to replace the fuel nozzle NOTE Before Removing Igniter Assembly it is recommended to unplug the control unit to pre 1 Remove Igniter Assembly vent accidental operation Figure 99b B Rotate Ignition Coil back to gain access to Ignit er Assembly A Using a flat head screw driver loosen the retain ing clips securing the ignition coil in place NOTE Prior to beginning this procedure be sure a label exists on the Blower Housing to indicate where the edge of the Escutcheon Plate should be aligned for proper Igniter Assembly placement If no label exists mark the Blower Housing on the right edge of the Escutcheon Plate Figure 99c C Remove the Fuel High Pressure Pipe Escutcheon Plate Spine Nut and the Escutcheon Plate D Rotate Igniter Assembly and Remove Page 108 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 APPENDIX E ANNUAL MAINTENANCE PROCEDURE 2 Replace Fuel Nozzle 3 Adjust Electrodes TIP GAP MARKS amp DC WASHER qur III TT T TTTTTTTTTTTTT ERVICE HOTLINE 1 B00 OlL BURN 1 gt 3 m h 3 IN PRESSURI Figure 100a Tip Gap top view Figure 101a A Adjust the Gap of the Electrodes using the Beck A Inspect Igniter Assembly for any sign of damage ett T Gauge gt y al 2 3 0 is POSTO
94. leasing all of the Diesel Burner Con 9 9 troller s wires Function 3 Remove the two screws securing the Diesel Burner Con The Diesel Burner Controller operates and monitors the Diesel Burner s components and safely shuts Aqua Hot off in the 4 Remove defective Diesel Burner Controller from the event of an overheat flame out or low voltage condition Aqua Hot Function Replacement Indicator If the Controller is damaged or fails to function properly 5 Align the replacement Diesel Burner Controller to the Aq ua Hot and reinstall the two screws previously removed Replacement Procedure tightening firmly NOTE The Diesel Burner does not need to be detached from 6 Connect Aqua Hot and Diesel Burner Controller s white electrical connections together and press down on the tabs to secure them together 1 Locate the Diesel Burner s white electrical plug connec tion to the Diesel Burner Controller then press back on the 7 Connect the Diesel Burner and Diesel Burner Controller s two tabs securing the two connections together Next pull ODONIS anid ices Gown On the two electrical plug connections completely apart the tabs to secure them together Figure 88 White Electrical Plugs Diesel Burner Controller Page 90 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 SEC
95. m when the 10 antifreeze solution enters the overflow tube attached to the expansion tank connection Once the systems have been purged disconnect the wire from the ground source and the terminal block Check the Aqua Hot s expansion tank and top it off to the cold level mark with the 50 50 antifreeze and water mixture if necessary Ensure that each thermostat s connection wiring is still in its original configuration Reference Appendix A Page 40 SECTION 5 FILLING THE AQUA HOT WITH HEATING SOLUTION Terminal Block for Switches Heat Exchanger Fans and Thermostats Figure 27 2 AO AI F2 Fi Te Ti DO DI L L T3 vies A A Zone 1 Thermostat Connection Terminal Zone 2 Thermostat Connection Terminal 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A page 41 SECTION 5 DRAINING THE AQUA HOT WITH HEATING SOLUTION WARNING Only propylene glycol based boiler type antifreeze deemed GRAS Generally Recognized as Safe by the FDA shall be used in the Aqua Hot s hydronic heating system Failure to use the above specified antifreeze type could result in serious injury or death CAUTION Ensure that the overflow tube is connected from the Aqua Hot s expansion tank connection to the expansion tank s bottom connection and from the expansion tank s top con nection through the overflow tube hole in th
96. n at 703 620 6003 www rvia com or writing to them at the following address visiting them online at Recreation Vehicle Industry Association 1896 Preston White Drive P O Box 2999 Reston VA 20195 0999 Arrows indicate directional flow of domestic water Fresh Water Storage Tank 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A Demand RV To Hot Water Faucets o D eo t6 Domestic d m D Hot Water m OUTLET _ 0 6 co 9 z T Domestic Cold Water lt INLET To Cold Water Faucets Page 99 APPENDIX D EXTREME COLD WEATHER OPERATION WARNING When storing the Motorhome Not winterizing the Aqua Hot when freezing temperatures are present will result in serious damage to the Aqua Hot s Domestic Water Heating System Also be sure to use an FDA approved GRAS rated antifreeze for winterization NOTE The Aqua Hot can continue to be used for interior zone heating once the domestic water heating system has been drained and winterized 120 Volt A C Electric Heating Element Please note that the 120 Volt AC Electric Heating Element is the Aqua Hot s secondary heat source for heating both the interior and or the domestic hot water during low heating de mand situations such as when moderate ambient t
97. nect the wires removed from the defective high limit thermostat to the replacement high limit thermostat 6 Test for proper operation Figure 14 DC High Limit Thermostats Reset Button Page 25 DC High Limit Thermostat Right The DC high limit thermostats serve as a safety measure in the event that the diesel burner continues to operate after the maximum operating temperature 1s reached The high limit thermostats allow the current for the diesel burner to pass through them until the boiler tank reaches a temperature of 215 F Should this temperature be reached the right high limit thermostat blocks the current to the diesel burner s fuel solenoid which prevents the diesel burner from operating Troubleshoot the right DC high limit thermostat if the fol lowing condition has occurred e The fuel solenoid on the diesel burner fails to operate e The diesel burner switch light flashes an 8 fault code Troubleshooting 1 Place a jumper wire between the black 8 and black 21 wires on the diesel burner s wire harness to by pass the right high limit thermostat Check the Aqua Hot for normal operation NOTE Bypassing the high limit thermostats is for testing only and must not be used for the Aqua Hot s nor mal functioning 2 Disconnect the right DC high limit thermostats wires then using an ohmmeter check the thermostat for conti nuity If there is no continuity complete the follow
98. ng Fault Indicator Light which by using a series of blinking lights indicates the particular component of the Diesel Burner that failed during operation Please reference Section 9 Switch Panel Blinking Fault Indicator Light for additional information Please note that the Diesel Burner is the Aqua Hot s prima ry heat source for heating both the interior and or the do mestic hot water such as when cool ambient temperatures exist and or when there is a high demand for domestic hot water 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A Electric Element Switch The Electric Element switch activates the Aqua Hot s 120 Volt AC Electric Heating Element reference Figure 5 This procedure allows the 120 Volt AC Electric Heating Element to operate and supply heat to the Aqua Hot s Boiler Tank which will heat the Aqua Hot s antifreeze and water heating solution to the maximum operating temperature of 190 5 F in approximately 1 2 hours The indicator light adjacent to the Electric Element switch will illuminate whenever the Electric Element switch 15 in the ON position Please note that the 120 Volt AC Electric Heating Element is the Aqua Hot s secondary heat source for heating both the interior and or the domestic hot water during low heating demand situations such as when moderate ambient tempera tures exist and or when there 1s a low demand for domestic hot water Page 15 SECTION 2 INTERIOR
99. nnections Diesel Burner s White Electrical Plug Diesel Burner Controller s White Electrical Plug White Electrical Plug Terminal Numbers Reference piece on plug Page 48 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 SECTION 6 DIESEL BURNER White Electrical Plug Terminal Numbers Rear View Figure 34 Reference piece on plug Yellow Cad Cell Yellow Cad Cell Orange Motor SIG Black Motor Red Ignition Coil Black Ignition Coil Violet Fuel Solenoid White Fuel Solenoid Pink Motor l 2 3 4 5 6 7 8 9 Page 49 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A E DIESEL BURNER SECTION 6 3 8Z0 002 301 a LJ I I ern YOLOW YIONVHDIG Avg O a LVISOWASHL JUNLVaadINAL E z 9uo7 did DAMI fa amp 81 gt 2 og 9uoz enig SE IDINOS 43MOd DAA 21 IM Lt EE IPAS SINCE nl RE AES FIRES 4 _ MoT li Moos V yr OVAOCI I M YOZ 200 6 C 3LIV SPO Opener poy HOM 4OLVORIN wory enderman 8679 589 008 1 MALE C oes IIAG ALN OANA 135 Fr g GN SVGISAS SINIV
100. ntinuity if continuity does not exist press the reset button on the High Limit Thermostat Check the vehicle s fuel supply to ensure that an adequate amount of fuel exists Check the Fuel Nozzle for obstructions or contaminants Check the Diesel Burner s Ignition Module for proper functionality Verify that the Igniter Assembly s electrodes are properly aligned The Diesel Burner switch has been turned on however multiple attempts are required before the diesel burner will ignite Check the Fuel Nozzle for obstructions or contaminants Check the Diesel Burner s Ignition Module for proper functionality The Aqua Hot s exhaust system sputters while the diesel burner is operating Check the Diesel Burner s Flame Sensor to ensure that the lens is clean and for proper functionality Check the Diesel Burner s Combustion Chamber for build up Check the exhaust pipe for damage or air flow restrictions The Aqua Hot s exhaust system produces white smoke after ignition Ensure that air bubbles have not made their way into the fuel system Check the Fuel Solenoid for proper functionality Check the Fuel Nozzle for obstructions or contaminants Check that the Igniter Assembly s electrodes are properly aligned Check for fuel leaks The Aqua Hot s exhaust system produced black smoke after ignition This 1s a result of the air fuel mixture being incorrect thus check the following Check the Fuel Nozzle for obstructions or contaminants C
101. o Diesel Burner is detached from the Aqua Hot refer beginning this replacement procedure ence the procedure for Detaching and Reattaching 1 Following the procedure for Detaching and Reattaching al for instructions CAUTION Be sure to remove the clamps from the Fuel Supply and Fuel the Diesel Burner located in Section 7 of this manual detach the Diesel Burner from the Aqua Hot 2 Move the Blower Motor and attached Blower Wheel back from the Diesel Burner l Return lines prior to starting the Diesel Burner A Using a 3 8 inch socket wrench loosen and remove the two bolts securing the Blower Motor s plate to the pl Housi E Blower Motor and ower Housing Figure 81 Blower M il XS B Pull the Blower Motor and Blower Wheel Assembly JU x out of the Blower Housing and away from the Diesel CC Burner being careful not to dislodge the Blower Mo tor s wiring 3 Reaching into the Blower Housing under the Air Guide A 4 Air Guide pull the defective Coupling straight out away from the OW LI Diesel Burner 7 ud J AI Blower Housing Page 84 O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 8 DIESEL BURNER COMPONENTS AND REPAIR INFORMATION Blower Wheel A DANGER A The Aqua Hot operates on both AC and DC power Be sure to disconnect the 120 Volt AC power supply prior to servicing Failu
102. o 15 in Ibs Do not overtighten shut down and that all power sources have been VELIS disconnected 6 Connect the replacement control thermostat s wires in the same configuration as the removed thermostat s 2 Locate the control thermostat for the electric wires element reference figure 12 7 Test for proper operation by using a digital 3 Disconnect the defective control thermostat s thermometer wires by separating the quick disconnect termi nals 4 Using a 5 8 wrench or socket remove the de fective control thermostat from the Aqua Hot NOTE The coach must either be plugged into shore power or the generator must be on for there to be 120vac at the heater E y Figure 12 M 185 F Control Thermostat Please note that the Diesel Burner has been removed in this image Page 23 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 AC High Limit Thermostat The AC high limit thermostat serves as a safety measure in the event that the electric heating element continues to oper ate after the maximum operating temperature is reached The high limit thermostat allows the current for the heating element to pass through it until the boiler tank reaches a tem perature of 215 F Should this temperature be reached the high limit thermostat blocks the current to the element which prevents it from continuing to provide heat to the boil er tank Troubleshoot th
103. ocate the AC wires connected to the AC relay pins 4 and 2 and remove the AC wires from the relay 3 Using an ohmmeter check the relay AC pins 4 and 2 for continuity If no continuity exists follow the instructions in this section to replace the AC relay Page 36 SECTION 4 AQUA HoT COMPONENTS AC Relay Replacement Procedure A DANGER FAILURE TO DISCONNECT ALL POWER SUPPLIES AND OR TO ALLOW THE HEATER TO COOL BEFORE SERVICING COULD CAUSE SERIUOS DAMAGE OR PERSONAL INJURY 1 Ensure that the Aqua Hot has been completely shut down and that all power sources have been disconnect ed 2 Also ensure that the motorhome is not connected to shore power and that a generator is not running during this replacement procedure 3 Locate the A C Relay on side of unit Reference Figure 22 for location of A C Relay 4 Release the wires from the defective A C relay by re moving the corresponding screw terminals 5 Remove A C Relay from the side of the heater 6 Attach the replacement A C relay to the side of heater 7 Using the wiring diagram in Appendix connect the wires previously removed to the replacement AC relay 8 Test for proper operation NOTE The motorhome must be plugged into shore power or the generator must be running for the electric element to be operational vet Tews LA J teeiarer pio1junag P 36304 Page 37 2009 Aqua Hot
104. of hot water and or interior heat NOTE The Aqua Hot is not designed to provide continuous hot water using the Electric Heating Element only Ensure that the motorhome 1s plugged into shore power or has the generator running Ensure the Aqua hot 1s not up to maximum operating temperature by checking it with a digital thermometer With the Interior Switch Panel s Electric Element switch on locate the Electric Element s 120VAC relay and check for DC volt age at Pin 0 and Pin 1 reference Appendix A Ensure that the 12 Volt switch is turned on and that the relay engages Test the VAC Relay to ensure that it 15 working properly using extreme caution A With the Electric Element switch on check for AC voltage at both VAC power supply terminals on the relay terminals 4 and 2 B Inspect the VAC Relay and the Relay s wires for damage C Turn the VAC Breaker off and disconnect both VAC power supply wires from the VAC Relay terminals Turn the Electric Element switch on and off while checking for continuity across the two open terminals on the VAC Relay If no continuity exists replace the VAC Relay Check the Electric Heating Element s High Limit Thermostat for continuity 1f no continuity press the reset button on the ther mostat Verify that the 120 Volt AC Electrical Heating Element is operating properly A Disconnect the motorhome from VAC shore power and switch off the motorhome s generator B Detach and rem
105. om the Diesel Burner 6 Usinga 5 16 inch socket wrench loosen and remove the bolt securing the Air Shutter to the Blower Housing 7 Remove the Air Shutter from the Diesel Burner 8 Usinga 5 16 socket wrench loosen and remove the bolt on the Air Band 9 Remove the defective Air Band from the Diesel Burner by sliding it off the Blower Housing 10 Install the replacement Air Band by sliding it onto the Blower Housing and inserting the bolt previously removed onto the Air Band and tightening the bolt 11 Install the Air Shutter back onto the Blower Housing and secure in place with the bolt previously removed NOTE Be sure the Combustion Air Indicator on the Air Shut ter falls correctly on the Blower Housing s Combus tion Air Adjustment Scale once installed 9 Insert the Fuel Pump Assembly and attached Coupling if applicable into the Blower Housing NOTE In order to connect the Fuel Pump Assembly to the Blower Motor with the Coupling it may be necessary to pull the Ignition Module back on its hinge and ro tate the Blower Wheel slowly until both the Blower Motor and the Fuel Pump Assembly are seated cor rectly on the Coupling 10 Secure the Fuel Pump Assembly to the Blower Housing with the two bolts previously removed 11 Reattach the Fuel Supply Tube Assembly to the Diesel Burner and Fuel Pump Assembly and tighten both hexago nal locknuts with a 7 16 inch open end wrench 12 Plug the Cord Se
106. ombination of the aforemen tioned functions If excess propylene glycol exists within an antifreeze and water heating solution the water s heat ab sorption properties are compromised which could ultimately inhibit the Aqua Hot from providing adequate domestic hot water and interior heating Additionally if the antifreeze and water heating solution contains over 70 percent antifreeze the freezing point 1s ac tually raised resulting in less freeze protection Page 14 SECTION 2 INTERIOR SWITCH PANEL 2Aqua Hot i DSUOFPICZ NOTE The Diesel Burner will ignite anytime the Diesel Burner switch is turned on even 1f it 1s turned back off before the Diesel Burner actually ignites IRATI Indicator Light Electric Element a NOTE This feature 15 only operational whenever the Motor home is connected to 120 Volt AC power or when the generator is operating Diesel Burner Switch The Diesel Burner switch activates the Aqua Hot s Diesel Burner reference Figure 5 This procedure allows the Diesel Burner to operate and supply heat to the Aqua Hot s Boiler Tank which will heat the Aqua Hot s antifreeze and water heating solution to the maximum operating temperature of 190 5 in approximately 10 20 minutes The indicator light adjacent to the Diesel Burner switch will illuminate whenever the Diesel Burner switch is in the ON position This light also incorporates a self diagnostic Blink i
107. or experiences leaks Figure 70 Hexagonal Locknut Fuel Supply Tube Hexagonal Locknut Fuel Pump Wa 2 DIN ANID Fuel Supply Tube Assembly Replacement Procedure NOTE The Diesel Burner does not need to be detached from the Aqua Hot for this replacement procedure 1 Loosen both hexagonal locknuts on either end of the Fuel Supply Tube Assembly with a 7 16 inch open end wrench 2 Remove the defective Fuel Supply Tube Assembly from the Diesel Burner 3 Install the replacement Fuel Supply Tube Assembly onto the Diesel Burner 4 Tighten each hexagonal locknut completely Assembly Fuel Pump Assembly A DANGER A The Aqua Hot operates on both AC and DC power Be sure to disconnect the 120 Volt AC power supply prior to servicing Failure to do so could result in serious personal injury electrical shock or even death 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A Function The Fuel Pump Assembly draws diesel fuel from the vehicle s main fuel tank and creates a preset pressure of 145 PSI required for proper fuel atomization Then when the signal is given the Fuel Pump Assembly s Fuel Solenoid Valve opens which allows the fuel to flow to the Fuel Nozzle where it is released to mix with the combustion air and ignited to es tablish a flame which heats the Aqua Hot s Boiler Tank Page 72 Replacement Indicator Replace if the Fuel Pump L
108. ot 375D Hydronic Heating System Service Manual Rev A 10 SECTION 4 AQUA HOT COMPONENTS Clean the 90 hose barb and straight hose barb fittings then wrap the 90 hose barb and the straight hose barb threads with Teflon tape Install the 90 hose barb and straight hose barb fittings on the replacement check valve ensuring that they are installed properly with the 90 hose barb on the arrow side of the check valve Reference Figure 17 Install the replacement check valve onto the Aqua Hot s boiler tank The arrow on the check valve must point towards the back of the boiler tank Slide the hoses back onto the replacement check valve and set the constant tension clamp back into place Refill the Aqua Hot s boiler tank with the antifreeze and water heating solution Reference Section 5 11 Test for proper operation Page 29 Tempering Valve The tempering valve for the Aqua Hot mixes the heated do mestic water from the boiler tank with cold domestic water at a preset ratio to reduce the risk of scalding Troubleshoot the tempering valve if the following condition has occurred e There isa lack of hot domestic water Troubleshooting 1 Inspect the tempering valve to ensure that it has not been leaking 2 Test the tempering valve s functionality by turning the knob 3 Test the temperature of the hot water using a digital thermometer at one of the hot water faucets Water Temperature should r
109. ove the Diesel Burner C Check the Electric Heating Element for continuity If no continuity replace the Electric Heating Element Page 96 O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A E WIRING DIAGRAM APPENDIX A p 2 2 2 2 2 2 3 ew 870 007 301 Tuus REC CE MEE 1 1 amp 2H 4nnaz K g ___ 1 1 mace L ISOWUSHL ee ae Ne eee HJ wozi lt 0 YOLYOKINE et c GH IHON 4O1VOSIM p HOBMS osiNOO 1770 I L Qvn NolwD 7 Do H M d JH 13H AV OH 1VISOVWeHI3HL 3uni veria m H CORVISOWRIBHL 1 INOZ X2018 TVNINB3I HO1IMS X90 1H34NI 5 IM Lt FE IPAS OOS lt 0 wu 8 135310 HLF IN SZL OVAOZL M YOZ OQAZUSeBDJIIOA cCOQ S 3HV I9pOlN apego uovdm 04 wory 8679 589006 PA MAAN y 8 ON SmNIISAS SNILWSH 430H enbye HOIH Sio P9 9 IN JINN HOH IVISOIWPBHI HOUNG 10714 99 1viSOMNu3H z 9uog dind EE B 4 Quo 8l 4858 9uoZ dnd A 19 SE YAMOd DAA 21 MOOSI 2vAOG L A8 _ 1N3 313 Page 97 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A APPENDIX B WIRE GAUGE CHART AMERICAN BOAT AND YACHT COUNCIL RECOMMENDATIO
110. ove the Escutcheon Plate from the Diesel Burner Replacement Indicator 7 Install the replacement Escutcheon Plate and align the right edge of the Escutcheon Plate with the edge of the Replace the Escutcheon Plate if it becomes lost or damaged label or mark 1f applicable Replacement Procedure 8 Insert and tighten the Escutcheon Plate s bolt to secure the NOTE Prior to beginning this replacement procedure be sure Escutcheon Plate to the Blower Housing a label exists on the Blower Housing to indicate where NOTE Verify that the Escutcheon Plate s right edge 15 the edge of the Escutcheon Plate should be aligned for aligned with the edge of the label or mark after it has proper Igniter Assembly placement If no label exists been tightened mark the Blower Housing on the right edge of the Escutcheon Plate 9 Install the Escutcheon Plate Spline Nut on the Igniter As The Diesel Burner does not need to be detached from sembly and tighten completely the Aqua Hot for this replacement procedure 10 Reattach the Fuel Supply Tube to the Igniter Assembly and tighten the hexagonal locknut 1 Loosen the Fuel Supply Tube Assembly s hexagonal lock nut on the Fuel Pump Assembly with a 7 16 inch open end wrench 11 Tighten the Fuel Supply Tube Assembly s hexagonal lock nut to the Fuel Pump Assembly NOTE The Fuel Supply Tube Assembly does not need to be completely removed
111. r out of the nozzle holder to prevent contami nation of the replacement nozzle 1 Turn the Diesel Burner Switch to the on po 3 Shut the Diesel Burner off and wait for unit sition to completely shut off 2 After the Diesel Burner has ignited inspect the exhaust for smoke NOTE The diesel burner can either be shut off by 1 Turning the Diesel Burner switch to the off position 2 Disconnecting the control thermostat wires 3 Shut the Diesel Burner off and wait for unit to completely shut off 3 Unplugging the diesel burner controller Reference Figure 94a NOTE The diesel burner can either be shut off by 1 Turning the Diesel Burner switch to the off position 2 Disconnecting the control thermostat wires 3 Unplugging the diesel burner controller Reference Figure 94a lt Aqua Hot ON Step 2 Replace the Fuel Filter Diesel Fiectric 1 Locate Fuel Filter Bumer Element 2 Using hose pinch off pliers clamp off both fuel lines going to the fuel filter Reference figure 94 3 Replace fuel filter with proper replacement canister NOTE It 1s recommended that the replacement fuel filter be filled with clean diesel fuel prior to installation 4 Remove hose pinch off pliers 10 Micron Diesel Burner Fuel Filter Controller Plug Page 103 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 APPENDIX E ANNUAL MAINTENANCE PROCEDURE Step 4
112. re to do so could result in serious personal injury electrical shock or even death Function The Blower Wheel creates a combustible air flow when rotated by the Blower Motor Replacement Indicator Replace the Blower Wheel if it 1s broken cracked or too worn to function properly Replacement Procedure CAUTION sure to clamp off the Fuel Return and Supply lines prior to beginning this replacement procedure 1 Following the procedure for Detaching and Reattaching the Diesel Burner located in Section 7 of this manual detach the Diesel Burner from the Aqua Hot 2 Move the Blower Motor and attached Blower Wheel back from the Diesel Burner A Using a 3 8 inch socket wrench loosen and remove the two bolts securing the Blower Motor to the Blower Housing B Pull the Blower Motor and Blower Wheel Assembly out of the Blower Housing and away from the Diesel Burner being careful not to dislodge the Blower Mo tor s wiring Coupling Blower Housing LL ES O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 3 Loosen the set screw on the Blower Wheel with a hexago nal wrench then slide the defective Blower Wheel off of the Blower Motor s shaft 4 Place a 0 030 1 32 1 64 inch Feeler Gauge on top of the Blower Motor then slide the replacement Blower Wheel onto the Blower Motor s shaft until it contacts the Feeler Gauge 5 Rotate the Blower Wheel until
113. rner has shut off turn on the inte 1 Replace Fuel Nozzle and Fuel Filter rior heat run hot water until the Diesel Burner cycles back on B Check antifreeze level in over flow bottle monthly C Run Diesel Burner Monthly D Run Interior Heating zones Monthly E Ifthey are going to winterize their motor home make sure they use the winterization antifreeze DO NOT BLOW OUT WITH AIR Page 111 O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A E Page 112 O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A E Page 113 O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A E ua Flot HYDRONIC HEATING SYSTEM 3 o D Aq SERVICE MANUAL 2 15549 East Highway 52 Fort Lupton CO 80621 2 ghway 52 Fort Lupton 2 Aq LI a b ot Toll free 800 685 4298 phone 303 659 8221 fax 303 857 7881 HEATING SYSTEMS INC www aquahot com Page 114 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5
114. rotection boil over pro tection and anti corrosion and rust protection a 50 50 mix ture of GRAS approved propylene glycol boiler antifreeze and water is recommended Reference Section 1 Antifreeze and Water Heating Solution for additional information regarding the antifreeze and water heating solution Be sure to use a GRAS boiler type pro pylene glycol based antifreeze rather than an RV and Marine antifreeze or an automotive antifreeze coolant If assistance is needed in selecting an appropriate antifreeze please contact the Aqua Hot Heating Systems Product Appli cation Department at 1 800 685 4298 1 Open the Aqua Hot s drain valve located at the front of the heater Reference Figure 25 Connect a piece of 1 2 inch PEX type tubing to the drain valve This piece should be long enough to transport the antifreeze and water heating solution from its source to the Aqua Hot Pafgod 19 SECTION 5 FILLING THE AQUA HOT WITH HEATING SOLUTION 3 Fill the Aqua Hot completely with the 50 50 mixture of antifreeze and water heating solution This will take approximately five gallons look for the solution to enter the overflow tube attached to the expansion tank con nection on top of the Aqua Hot 4 When refilling open the air release valve located on the expansion tank connection to release air pockets Refer ence Figure 24 Hold the valve open until all air 1s re leased Be sure the valve is closed when f
115. s Front Open Access Back 0 inches Top 6 inches Sides 0 inches Install in strict compliance with local codes NFPA 1192 and the manufacturer s instructions Page 8 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 1 INTRODUCTION TO THE AQUA HorT 375D WARNING WARMING Expansion Tank Connecton Page 9 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 1 INTRODUCTION TO THE AQUA HorT 375D 120 Volt AC Figure 3 p e e Zone 1 Relay Zone 2 Relay Fuse Block Page 10 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 SECTION 1 INTRODUCTION TO THE AQUA HorT 375D Diesel Burner High Limit Thermostats m Float Switch Low Temp Cut off Thermostat Diesel Burner Control Thermostat 1 INTERLOCK SWITCH 7 SYSTEM DRAIN 2 ZONE 1 RELAY 8 DIESEL BURNER CONTROLLER 3 ZONE 2 RELAY 9 DIESEL BURNER CONTROL THERMOSTAT 4 FUSE BLOCK 10 LOW TEMPERATURE CUT OFF THERMOSTAT 5 CIRCULATION PUMP ZONE 1 11 FLOAT SWITCH 6 DIESEL BURNER 12 DIESEL BURNER HIGH LIMIT THERMOSTATS Electric Element High Limit Thermostat 13 Electric Element Control Thermostat Page 11 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 SECTION 1 INTRODUCTION TO THE AQUA HOT 375D AQUA HOT OPERATIONAL Heat Source is selected from the Interior Switch Panel F
116. s Section 6 Diesel Burner General Recommended Page 43 General Component OVeErIVIGW Page 44 Diesel Burner Operational Overview Page 45 46 STS ANNO N 47 CONTONE cal 0 6 errr TEE EET Page 48 Schema liG ice m PER Page 49 Controller 560808916 sess sedans RES RA ton udis UpseALI SET itas MAS DM SQ UPS Page 50 51 Section 7 Detaching and Reattaching the Diesel Burner Detaching the Diesel B NT ssc cereo rot eit e eae ee teta oe ette uiae ais Page 52 55 Ieattaching tne Diesel BUtrier RUE esp PE IR E EI EE PPM ED Page 56 59 Section 8 Diesel Burner Components and Repair Information Diesel Burner Component Overview nennen nnne nennen nnns Page 60 E 61 All TUDE ASSeITIDIV DM MM OD M INE Page 61 62 FUGI NOZA ooa a Page 62 63 IONEL ASSEMDI V iarsa gE ee Page 64 Ignition Electrode Adjustment and CICAning ccccccseccseecseeceeeceeeseeeeeeeeeeteeeseeeseeeaes Page 65 66 LOFTON IVMIOGUICWASSEIMDIN xrar C Page 67 CI 6 C 295 C II inania dci mtn
117. s the chassis ground still properly grounded ze e pa Fault Code 10 1 Did the Flame Sensor see light and interpret it as fire 2 Isthe Fuel Valve stuck open Page 92 O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A E SECTION 10 TROUBLE SHOOTING This troubleshooting section has been separated into various WARNING Aqua Hot troubleshooting scenarios which may be experi enced by the heater This troubleshooting section will begin The Aqua Hot operates on both AC and DC power Be with the most probable cause of failure and the corresponding sure to disconnect the 120 Volt AC power supply from the remedy and will advance to the least probable cause and reme Aqua Hot prior to servicing Failure to do so could result dy in order to expedite the troubleshooting process and pin in serious personal injury electrical shock or even death point the problem quickly If additional assistance 1s needed please contact the Aqua Hot Heating Systems Technical Sup NOTE Be sure to check the Interior Switch Panel s Diesel port Department by phone at 1 800 685 4298 Monday through Burner switch for a blinking fault code prior to com Friday 7 00 AM to 4 00 PM Mountain Standard Time or pleting the following troubleshooting procedures through Aqua Hot Heating Systems website by going to www aquahot com and clicking on the Contact Us link then Please note that due to the Interlock Safety Switch
118. severed wires If no wires are found to be damaged or severed continue 5 Verify the functionality of the Float Switch by comple ting the following A Disconnect the wires from the Float Switch B Install a jumper wire between the wires on the har ness 65 amp 66 in order to bypass the Float Switch If the diesel burner and or electric heating element come on when the jumper wire is installed follow the instructions in this section to replace the float switch NOTE The Float Switch can be tested by performing a Continuity Test With the heater full of antifreeze there should be continuity between the wires on the Float Switch O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 4 AQUA HOT COMPONENTS Replacement Procedure A DANGER A FAILURE TO DISCONNECT ALL POWER SUPPLIES AND OR TO ALLOW THE HEATER TO COOL BEFORE SERVICING COULD CAUSE SERIOUS DAMAGE OR PERSONAL INJURY 1 Ensure that the Aqua Hot has been completely shut down and that all power sources have been disconnect ed Also because this replacement procedure will involve the boiler tank and the potential for hot coolant be sure the heater has adequately cooled 2 Drain the antifreeze and water heating solution from the Aqua Hot s boiler tank using the drain valve Approxi mately 2 gallons will need to be drained 3 Disconnect the float switch s wires by separating the quick disconnect terminals
119. socket remove the defective low temperature cutoff thermostat from the Aqua Hot 5 Install the replacement low temperature cutoff thermo stat tightening only to 15 in Ibs Do not overtighten 6 Connect the replacement low temperature cutoff ther mostat s wires in the same configuration as the removed thermostat s wires 7 Test for proper operation Page 27 Valves Interior Zone Check Valve Check valves are installed into the zone outlet ports for each heating loop to ensure that the antifreeze and water heating solution only flows in one direction If the heating solution attempts to backflow into the boiler tank the check valve closes to prevent that from happening Troubleshoot the check valves if the following condition has occurred e There is a lack of interior heat in a particular zone Troubleshooting 1 Verify that the heating zone is operating properly by checking the following A Check the Room Thermostat to ensure it should be calling for heat SECTION 4 AQUA HoT COMPONENTS Figure 16 Low Temp Cut off Thermostat B Check the circulation pump for operation by visual ly inspecting it for rotation of the pump 2 With the circulation pump operating tap on the check valve and wait five minutes to evaluate 11 interior heat is now present If interior heat is present after tapping the check valve the check valve was stuck closed and no further action 1s necessary
120. stem Service Manual Rev A 5 1 The Interior Switch Panel s Diesel Burner switch is moved to the ON position authorizing the Diesel Burner to be used as a heat source SECTION 6 DiESEL BURNER 8 The Blower Motor is activated which rotates the Blower Wheel to create combustible air and prepares the Fuel Pump Assembly for opera tion 14 The Diesel Burner Controller verifies that the Interior Switch Panel s Diesel Burner switch is still ON 2 The Flame Sensor checks for an existing flame 3 The input voltage is checked to ensure that it is greater than 10 volts 4 The Indicator Light on the Interior Switch Panel s Diesel Burner switch is activated 5 The Control Thermostat is checked to determine if there is a need for additional heat 6 The Ignition Module is activated 7 The Diesel Burner Controller verifies the presence of voltage at the Ignition Module to ensure that it has been activated 9 The Diesel Burner Controller verifies the presence of voltage at the Blower Motor to ensure that it has been activated 10 The Fuel Pump Assembly s Fuel Solenoid Valve is activated which sprays diesel fuel into the Combustion Chamber which is ignited by the Ignition Module s Electrodes 12 The Ignition Module is de activated 11 The Flame Sensor verifies that a flame is present 13 The Control Thermostat is checked to ensure there is still a need for heat 15 The
121. t back into the Fuel Pump Assembly s Fuel Solenoid Valve 13 Following the procedure for Detaching and Reattaching the Diesel Burner located in Section 7 of this manual reattach the Diesel Burner to the Aqua Hot Page 78 SECTION 8 DIESEL BURNER COMPONENTS AND REPAIR INFORMATION NOTE The Mounting Gasket must be replaced each time the Setting the Combustion Air Level Diesel Burner is detached from the Aqua Hot refer ence the procedure for Detaching and Reattaching For information regarding setting the Diesel Burner s Combus the Diesel Burner located in Section 4 of this manu tion Air level please contact the Technical Support Depart al for instructions ment at 1 800 685 4298 CAUTION Be sure to remove the clamps from the Fuel Supply and Fuel Return lines prior to starting the Diesel Burner Failure to do so could result in serious damage to the Diesel Burner Fuel Pump Assembly s Fuel Solenoid Valve Air Band Combustion n Fuel Supply Air Indi Tube Assembly SS gt umm D gt Bolts to be removed on the Fuel Pump Assembly 7 Fuel Pump D Assembly Cord Set Figure 76 Combustion Air Scale on Blower Housing Page 79 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 5 SECTION 8 DIESEL BURNER COMPONENTS AND REPAIR INFORMATION Escutcheon Plate Spline Nut A DANGER A The Aqua Hot operates on both AC and DC power Be
122. t created until its boiling point 1s reached it 1s at this point that the liquid turns to a gas and is expelled to prevent the heating system from overheating Each time the boiling point is reached a loss of efficiency occurs because the heat pro duced is expelled rather than used for the function of the heating system Therefore a higher boiling point 1s desired in order to combat the loss of efficiency which allows the antifreeze to transport the heat created from the internal pro cess throughout the motorhome where it can be used produc tively rather than dissipating due to its change from a liquid to a gas Rust and Anti Corrosive Inhibitors Another major function of antifreeze 1s to provide protection to the internal metal components of the Aqua Hot hydronic heating system from corrosion and rust Antifreeze is able to perform this function by the addition of rust and anti corrosive inhibitors which are designed specifically to acti vate in a water solution Summary Antifreeze has three basic functions freeze protection boil over protection and anti corrosion and rust protection O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A Antifreeze is also primarily responsible for heat transfer characteristics Therefore as water 1s an excellent heat con ductor it is added to the mixture A 50 50 solution of pro pylene glycol antifreeze and water 15 recommended to pro vide the best performance c
123. the Flame Sensor Socket into place by gently press ing down on the rear of the Flame Sensor Socket and push ing back toward the clip while wiggling the Flame Sensor Socket slightly until the Flame Sensor Socket moves into place Place the Flame Sensor Gasket onto the tabs on the under side of the Ignition Module Assembly Close the Ignition Module Assembly and secure with the Ignition Module Retaining Clips Ignition Module Assembly Bottom View Clip on Ignition Module Assembly to secure the Flame Sensor Socket in place Assembly Flame Sensor Gasket Socket Ss Flame Sensor Me ignition Module Flame Sensor Figure 69 Flame Sensor Flame Sensor Socket Flame Sensor Gasket Flame Sensor Mounting Bracket Ignition Module Retaining Clips Ignition Module Assembly Figure 29 Flame Sensor Mounting Bracket Page 71 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A Fuel Supply Tube Assembly A DANGER A The Aqua Hot operates on both AC and DC power Be sure to disconnect the 120 Volt AC power supply prior to servicing Failure to do so could result in serious personal injury electrical shock or even death Function The Fuel Supply Tube Assembly transports the Diesel Burner s fuel from the Fuel Pump Assembly to the Igniter As sembly Fuel Tube Replacement Indicator Replace the Fuel Supply Tube if it becomes broken damaged
124. the locking tabs and pulling the inter lock switch 3 Remove the defective interlock switch from the Aqua Hot 4 Install the replacement interlock switch onto the Aqua Hot ensuring that the locking tabs snap into place 5 Connect the Aqua Hot s wires to the replacement inter lock switch with yellow wire 31 connected to the ter minal labeled NO and yellow wire 9 connected to the terminal labeled COM NOTE If the interlock switch s wires are reversed the in terlock switch will only allow the diesel burner to operate when the access cover 1s removed and the button on the switch 1s released Interlock Switch Button Locking Tab Connect Wire 31 NO Page 18 Float Switch The Float Switch monitors the level of antifreeze and water heating solution within the Aqua Hot s boiler tank to ensure that an adequate volume exists Reference Figure 9 for loca tion Troubleshoot the Float Switch if one of the following condi tions has occurred e The diesel burner and or electric heating element fails to operate Troubleshooting 1 Verify that the Aqua Hot s boiler tank is full of the anti freeze and water heating solution 2 Verify that the connections for the wires on the float switch are securely plugged into the wiring harness 3 Verify Fuse and the Fuse Block is sending power to the float switch 4 Inspect the wire harness for damaged or
125. tic Water Heating System reference Figure 89 1 Completely drain the fresh water storage tank 2 Disconnect the domestic water demand pump s suction line from the fresh water storage tank 3 Attach an adequate piece of hose onto the suction side of the domestic water demand pump 4 Place the opposite end of the hose into an adequate supply of FDA approved GRAS RV Antifreeze and turn on the demand water pump 5 Open and close all interior and exterior water faucets one at a time until only pure RV Antifreeze is present Perform this procedure for both the hot and cold faucets 6 Turn off Demand Water pump and remove the hose and re connect the domestic water demand pump s suction line to the fresh water storage tank WARNING An FDA approved GRAS rated winterization antifreeze must be used YOU CANNOT BLOW DOMESTIC WATER COIL OUT WITH AIR TO WINTERIZE AQUA HOT De Winterizing the Domestic Water Heating System For de winterization completely fill the fresh water storage tank Turn on demand water pump and open and close all interior and exterior water faucets one at a time until only clear water is present visible Reference Figure 89 If disinfecting the potable water system after de winterizing be sure to follow RVIA s Instructions for Disinfection of Potable Water Systems on Recreation Vehicles These instructions can be obtained by contacting the Recreational Vehicle Industry Associatio
126. to be detached from the Aqua Hot for this replacement procedure 1 Loosen the two screws securing the Ignition Module Re taining Clips and rotate both clips to release the Ignition Module Assembly Then tilt the Ignition Module Assem bly back on its hinge 2 Remove the existing Ignition Module Gasket from the Ignition Module Assembly 3 Apply the replacement Ignition Module Gasket to the un derside of the Ignition Module Assembly NOTE Be sure the Ignition Module Gasket is firmly secured in place to avoid fragments of the Gasket interfering with the operation of the Diesel Burner Ignition Module Assembly jg n Ignition Module p Gasket a m T pes Flame Sensor a Gasket NES i NC Flame Sensor Flame Sensor and Flame Sensor Socket O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A DAVEE CON E gt EA 1 In 4 Close the Ignition Module Assembly and secure with the LJ IN Ignition Module Retaining Clips Flame Sensor Gasket Replacement Procedure 1 Loosen the two screws securing the Ignition Module Re taining Clips and rotate both clips to release the Ignition Module Assembly Then tilt the Ignition Module Assem bly back on its hinge 2 Remove the Flame Sensor Socket from the underside of the Ignition Module Assembly by loosening the Flame Sensor Gasket from the tabs and sliding the Flame Sen sor s Mounting Bracket forward until it 1s
127. to the Diesel Burner Reference Fig 61 2 Loosen the two screws securing the Ignition Module Re taining Clips and rotate both clips to release the Ignition Module Then tilt the Ignition Module back on its hinge 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A Figure 60 Loosen and remove the Escutcheon Plate Spline Nut from the Escutcheon Plate Reach into the Blower Housing and pull the Igniter As sembly out of the Diesel Burner NOTE To ease the removal of the Igniter Assembly rotate the Igniter Assembly 180 from the installed position while removing the Igniter Assembly from the Air Tube Assembly If it continues to be difficult to re move the Igniter Assembly the Escutcheon Plate screw securing the Escutcheon Plate to the Blower Housing can be removed however be sure to align the edge of the Escutcheon Plate back to the edge of the label and secure with the Escutcheon Plate screw Insert the replacement Igniter Assembly into the Air Tube Assembly and align the Fuel Supply Tube back with the Escutcheon Plate Tighten the Escutcheon Plate Spline Nut onto the Fuel Supply Tube to secure it into place Close the Ignition Module and secure with the Ignition Module Retaining Clips Secure the Fuel Supply Tube to the Diesel Burner and tighten both hexagonal locknuts completely NOTE Ensure that the Escutcheon Plate is set to the edge of the indicator label on the Blower Housing
128. to the Fuel Pump Assembly within the Blower Housing there fore it may be necessary to pull the Ignition Module Assembly back on its hinge and rotate the Blower Wheel slowly until the Blower Motor is seated cor rectly on the Coupling and moves into place Thread the Blower Motor s wires into the Blower Housing through the small hole in the Blower Housing then back out through the Diesel Burner s Wiring Access Hole Connect the Blower Motor s Pink positive wire to the 9 terminal yellow orange signal wire to the 3 terminal and the black ground wire to the 4 terminal on the Die sel Burner s white electrical plug reference Appendix A Following the procedure for Detaching and Reattaching the Diesel Burner located in Section 4 of this manual reattach the Diesel Burner to the Aqua Hot NOTE The Mounting Gasket must be replaced each time the Diesel Burner is detached from the Aqua Hot refer 12 ence the procedure for Detaching and Reattaching the Diesel Burner located in Section 7 of this manu al for instructions Connect the Diesel Burner and Diesel Burner Controller s white electrical connections together and press down on the tabs to secure them together CAUTION Be sure to remove the clamps from the Fuel Supply and Fuel Return lines prior to starting the Diesel Burner Page 87 SECTION 8 DiESEL BURNER COMPONENTS AND REPAIR INFORMATION Figure 84
129. tric heating element fails to operate Troubleshooting 1 Disconnect the AC power source to the motorhome unplugging from shore power or shutting off the gener ator 2 Turn the electric element switch on the interior switch panel 3 Using a voltmeter check pin AI on the terminal block for 12 Volts DC Ifno voltage is present A Check the B fuse on fuse block for power If no power is present check fuse B If fuse is good follow troubleshooting guide for float switch 4 Using a Voltmeter check pin on terminal block for power If no power is present follow troubleshooting guide for the electric element switch B If12 Volts of DC power are present continue O 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A SECTION 4 AQUA HOT COMPONENTS 5 Locate the VAC relay A Check pins 1 amp 0 for 12 VDC power and ground 1 Pin lis and Pin 015 If there is no 12VDC and present 1 check wires for damage or loose connec tions 2 Follow the instructions in this manual for trouble shoot the Electric element Control thermostat A DANGER FAILURE TO DISCONNECT ALL POWER SUPPLIES AND OR TO ALLOW THE HEATER TO COOL BEFORE SERVICING COULD CAUSE SERIOUS DAMAGE OR PERSONAL INJURY B Ensure that all the A C power supplies to the coach have been disconnected 1 Turn the electric switch to the on position and Verify it is sending 12VDC power to the A C relay 2 L
130. ugh the Blower Housing until the Blower Motor s wires are free from the Diesel Burner NOTE It may be necessary to clip off and remove the wire ties bundling the Diesel Burner components wires together in order to free the Blower Motor s wires for removal 4 Using a 3 8 inch socket wrench loosen and remove the two bolts securing the Blower Motor to the Blower Hous ing 5 Remove the defective Blower Motor and attached Blower Wheel from the Blower Housing 6 Remove the Blower Wheel from the defective Blower Mo tor A Loosen the set screw on the Blower Wheel with a hex agonal wrench then slide the Blower Wheel off of the defective Blower Motor s shaft 7 Install the existing Blower Wheel onto the replacement Blower Motor A Place a 0 030 1 32 1 64 inch Feeler Gauge on top of the replacement Blower Motor then slide the Blower Wheel onto the Blower Motor s shaft until it contacts the Feeler Gauge 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A B Rotate the Blower Wheel until the set screw is cen tered on the flat of the Blower Motor s shaft C Using a hexagonal wrench tighten the set screw to secure the Blower Wheel in place Insert the Blower Motor and Blower Wheel Assembly into the Blower Housing and secure it with the two bolts previ ously removed NOTE The Blower Motor and Blower Wheel Assembly con 10 11 nects with the Coupling which connects
131. ute Purge checked to determine if there is a Cycle takes place need for additional heat 22 The Blower Motor is de activated Chart 2 Continued 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A 28 The Diesel Burner Controller will continue a cycle of checking the following until the Control Thermo stat calls for heat ensuring that the Power Emer gency Cutoff Relay is closed ensuring that there is no flame checking the input voltage to ensure that it is greater than 10 volts ensuring that the Interior Switch Panel s Diesel Burner switch s indicator light is illuminated ensuring that the Blower Motor does not have voltage indicating that it is operating checking for voltage at the Ignition Module to ensure that it is not active checking the Control Thermostat to determine if it is calling for heat Page 46 SECTION 6 DIESEL BURNER Model Type Model ARV Series Oil Burner SERIAL NUMBER SS 040824 23513 IIIIIIIIIIIIII Fuel Flow Rate 0 40 0 50 GPH 12VDC 20A Voltage Amperage R W Gec ett Corp Elyria Ohio Made in the U S A MP 1192 VSI 101 R02 2 Aqua Hot HYDRONIC HEATING SYSTEM Diesel Burner Model Number Diesel Burner Page 47 2009 Aqua Hot 375D Hydronic Heating System Service Manual Rev A E SECTION 6 DiESEL BURNER Press back on the tabs to release the white electrical co

SERVICE MANUAL - Aqua-Hot Heating Systems, Inc.

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