SERVICE MANUAL - Bock Water Heaters
Contents
1. Check voltage across lower terminals of contactor s Illustration 15 25 SERVICE PROCEDURE XI Thermostat Removal and Replacement Surface Mounted Thermostat Removal and Replacement A WARNING 1 STOP DANGER Turn power OFF to water heater High voltage exposure To avoid hazard to life or property be sure power is turned from inside of control box Remove plastic cover from d thermostat POCET Ur 3 Disconnect wires from thermostat terminals It may be necessary to label wires for proper reconnection to new thermostat 4 Note thermostat temperature setting for proper setting of new thermostat 5 Slide thermostat upwards and out of mounting bracket 6 Use a stiff brush to remove any debris or loose scale from tank surface where new thermostat will be installed 7 Slide new thermostat down into thermostat bracket until it snaps into place IMPORTANT thermostat must set completely flat or flush to tank surface An improperly installed thermostat will cause improper water heater operation 8 Refer to the wire diagram located on the inside of the upper control box cover and reconnect wires to the thermostat Be sure wire connections are snug and corrosion free Do not over tighten as that may damage thermostat 9 Set thermostat to the original thermostat setting found on the old thermostat 10 Restore power to water heater and ver2. 6 Turn power ON to water heater 7 Use caution and check voltage across terminals L1 and L4 for all thermostats see illustration 6 A Rated voltage IS present ECO is okay B Rated voltage NOT present proceed to step 8 Illustration 6 8 Turn power OFF to water heater and firmly press ECO reset button on thermostat s Turn power ON to water heater and recheck voltage across terminals L1 and L4 of thermostat s A Rated voltage IS present the ECO has previously opened indicating the water in the tank at some point did overheat Check the following 1 Thermostat must be in full contact with tank 2 Besure heating element s is not shorted to ground see Page 15 3 Proper thermostat operation see Page 21 B Rated voltage NOT present water in tank may be overheated 1 If water is overheated turn OFF power to water heater and flow water through tank to cool below set point of upper thermostat Reset ECO and recheck voltage 2 If water is cool replace thermostat s 18 SSS SSS QQQqQ_ _ LS EE SS SS SS SEE ee SERVICE PROCEDURE V High Limit ECO Testina High Limit Control ECO Testing for 600V Surface Thermostat Models A WARNING High voltage exposure To avoid hazard to life or property use extreme caution when 1 This procedure assumes line voltage transformer fuses and making voltage checks thermostat are in working order
3. Terminal Block C Manufacturer Identification Illustration 21 SERVICE PROCEDURE XVI Anode Rod Inspection and Replacement Anode Rod Inspection and Replacement A WARNING 1 STOP DANGER Turn power OFF to water heater High voltage exposure To avoid hazard 2 Turn off cold water supply to heater Connect hose to drain to life or property be aUe power is turned spigot of water heater and route to an open drain Opena OFF to water heater while performing this nearby hot water faucet to vent heater for draining Open procedure drain spigot of water heater and allow heater to drain to a point below the anode rod locations at the top of the tank 3 Close drain spigot and remove hose A WARNING 4 Remove the plastic anode rod access plugs at the anode Heater components and stored water may be rod locations HOT when performing the following steps in this procedure Take necessary precaution to 5 Remove anode rods from the water heater using a 1 1 16 prevent personal injury socket wrench 6 Visually inspect anode rods Anode rods should show signs of depletion this is normal If depletion is 1 2 of the original anode rod diameter original diameter is approximately 3 4 replacement is recommended If any of the steel core of the anode rod is exposed replacement is recommended 7 Upon completion of inspection and or subsequent replacement of the anode rod reinstall the anode into the
4. 2 Turn power OFF to water heater ECO reset 3 Remove lower control box cover and remove insulation from inside of control box O button 4 Use caution and check continuity across terminals 1 and 2 see illustration 7 J B San No al A Continuity IS present ECO is okay r G B Continuity NOT present proceed to step 5 YO oa Ok 5 Turn power OFF to water heater and firmly press ECO reset button on 5 P aron thermostat s Turn power ON to water heater and recheck continuity across mwj 4 terminals 1 and 2 of thermostat s g A Continuity IS present the ECO has previously opened indicating the water in Illustration 7 the tank at some point did overheat Check the following 1 Thermostat must be in full contact with tank 2 Be sure heating element s is not shorted to ground see Page 15 3 Proper thermostat operation see Page 22 B Continuity NOT present water in tank may be overheated 1 If water is overheated turn OFF power to water heater and flow water through tank to cool below set point of upper thermostat Reset ECO and recheck continuity 2 If water is cool replace ECO High Limit Control ECO Testing for Contactor Models Switch Contacts Normally closed Open on rise 196 F 4 F Manual Reset 1 Determine of high limit ECO has actuated This can be done by simply depressing the reset buttons If you hear and
5. Commercial Electric Energy Saver Water Heater IMMERSION AND SURFACE MOUNTED THERMOSTAT MODELS SERVICE MANUAL Troubleshooting Guide and Instructions for Service To be performed ONLY by qualified service providers For Models 50 A SF CF 80 A SF CF 120 A SF CF Denotes kW Rating Denotes Wiring Code Manual 238 47174 00B Save this manual for future reference Commercial Electric Water Heaters Table of Contents Page Service Procedure Introduction Tools 2 General Information 3 Sequence of Operation 10 Troubleshooting 13 Heating Element Testing 15 Line Voltage Testing 16 II Fuse Testing 17 III High Limit ECO Testing Surface Mounted 18 IV High Limit ECO Testing Surface Mounted 600V 19 V High Limit ECO Testing Contactor Models 20 VI Thermostat Operation Testing Surface Mounted 21 VII Thermostat Operation Testing Surface Mounted 600V 22 VIII Thermostat Operation Testing Contactor Models 23 IX Contactor Operation Testing 24 X Thermostat Removal amp Replacement Surface Mounted 26 XI Thermostat Removal amp Replacement Contactor Models 27 XII ECO Removal amp Replacement Contactor Models 28 XIII ECO Removal amp Replacement Surface Mounted 600V 29 XIV Heating Element Removal amp Replacement 30 XV Anode Inspection amp Replacement 31 XVI Generic Parts List 32 Glossary of Terms 33 Introduction This service manual is desig
6. Serial No ZB2564812 Cap 50 gal 189 3 liters Press Test 300 psi Working 150 psi Volts 240 Max Temp 180 Phase Three Amps 29 KW Each 4 TotalkW12 3 Elements Wattage rating based upon 60 Hz Electrical Characteristics Typical Rating Plate Located on Front of Water Heater GENERAL INFORMATION Contactor Models General Controls Layout H Ground Lug Terminal Block Upper Control Box gt Fuse Block s Contactor s ai ii High Limit ECO e UE Direct Immersion Bulb irect Immersion Bu o Lil lt High Limit ECO Control Q i OT Immersion Thermostat Lower Control Box gt O lt _ re gt e O ef o 0 a Heating Elements amp i Surface Mounted Thermostat Models General Controls Layout P i Lug JE MINA Block Upper Control Box gt dd p Fuse Block s Lower Control Box gt Surface Mounted Thermostats with ECO Heating Elements GENERAL INFORMATION 600V Surface Thermostat w Contactors Models General Controls Layout Ground Lug Terminal Block Upper Control Box Contactor s High Limit ECO Control Surface Thermostats Lower Control Box Heating Elements GENERAL INFORMATION Surface Mounted Thermostats Surface mounted thermostats are mounted into a bracket above each heating el
7. Fax 608 327 3300 Email sales bockwaterheaters com www bockwaterheaters com
8. NT J U U UU U BUSS BUSS 4 Set multi meter to volts AC Be sure to scale meter for R J appropriate voltage a a 5 Use caution and turn power ON to water heater JE Check voltage across 6 Use caution and check voltage across top terminals where top terminals service voltage connects to water heater see illustration 3 A Rated voltage IS present power to the water heater is Illustration 3 okay B Rated voltage NOT present check service panel Three Phase Line Voltage Testing Line voltage from Line voltage from service panel service panel 1 STOP DANGER Turn power OFF to water heater connected to Terminal block OR connected to Fuse block of heater of heater 2 Open upper control panel door 3 Determine connection point for line voltage from service panel terminal block or fuse block a 4 Set multi meter to volts AC Be sure to scale meter for appropriate voltage 5 Use caution and turn power ON to water heater 6 Use caution and check voltage across top terminals where service voltage connects to water heater see illustration 4 Check voltage across top terminals S S Y A Rated volt
9. Page 17 6 Refer to table below if items 1 through 5 above do not correct problem SYMPTOM No Hot Water Not Enough Hot Water or Continues Operation Slow Hot Water Recovery Overheated Water Noisy singing or hissing Elements Noisy Contactor PROBABLE CAUSE No power to heater Blown water heater fuses Loose wire connections Inoperative heating elements Inoperative thermostat s Open ECO Inoperative contactor s Inoperative heating element Sediment or lime buildup on element s Thermostat s set too low Inoperative thermostat s Inoperative contactor s Loose wire connection High demand period Undersized heater 9 Very cold inlet water to heater 10 Plumbing connections reversed Sediment or lime buildup on element s Loose wire connections Inoperative thermostat s Inoperative contactor s Derated heating element installed Surface thermostat s not flush with tank Grounded heating element s Thermostat set too high Inoperative thermostat s Inoperative ECO Lime formation on element s High or low line voltage Low line voltage Debris between contactor plates Incorrect or defective operating coil Loose wire connections CORRECTIVE ACTION 1 Check circuit breakers at service panel 2 Check water heater fuses 3 Check all wire connections 4 Check heating element s 5 Chec
10. age IS present power to the water heater is okay Illustration 4 B Rated voltage NOT present check service panel 16 Fuse Testing 1 STOP DANGER Turn power OFF to water heater 2 Open upper control box to allow access to fuse block 3 Locate fuse block and remove fuses 4 Set multi meter to the ohms setting 5 Check continuity across fuse see illustration 5 A Continuity IS present fuse is okay B Continuity NOT present replace fuse SERVICE PROCEDURE III Fuse Testing A WARNING High voltage exposure To avoid hazard to life or property be sure power is turned OFF to water heater while performing this procedure Illustration 5 17 SERVICE PROCEDURE IV High Limit ECO Testina High Limit Control ECO Testing for Surface Thermostat Models NOT including 600V A WARNING High voltage exposure To avoid hazard to life or property use extreme caution when 1 This procedure assumes line voltage and fuses are in working makina voltaae checks order 2 This procedure illustrates testing of just one surface thermostat Repeat this procedure for all surface thermostats on the water heater J ECO reset button 3 Turn power OFF to water heater 4 Remove lower control box cover and remove insulation from inside of control box 5 Remove plastic cover from thermostat s
11. al Block or Incoloy Sheath 0642 4500W 240V C02404524 l S Z Z lt o gt Lc Cy Coy Terminal Block Screw Element Rating Ink Stamped on Side of Terminal Block GENERAL INFORMATION Commonly Used Formulas Single Phase Balanced 3 Phase Watts B Watts 7 _ Volts Amps Volt Amps Volts x 1 732 Watts Amps x Volts Ohms Na Common Service Wire Configurations 240V 1Ph BLACK GREEN Ungrounded Grounding RED Ungrounded 240 oda 120 120 208 3Ph 240 3Ph 480 3Ph 277 1Ph Neutral A B C Neutral A B C Neutral A B C 120 120 otf 120 120 21 1 120 Sa 208 120 p 240 21 7 p 480 208 208 240 240 480 480 RED BLACK RED RED BLACK RED RED BLACK RED Commonly Used Formulas 6 288 166 250 144 216 91 83 125 72 58 9 432 2350 372 216 324 136 125 187 108 87 SEQUENCE OF OPERATION Bock s commercial electric water heaters can use either immersion thermostats contactor models or surface mounted thermostats Sequence of operation for each configuration is explained below It would be impractical to show all wire diagrams applicable to both configurations A typical wiring diagram is illustrated to aid in understanding the principles of the operating sequence Immersion Thermostats Contactor Models Configured to use a single immersion thermostat to control one or more
12. connection to the new control 5 Remove the two ECO mounting nuts holding the sensor to the tank Take care not to damage the mounting studs 6 Fasten the replacement ECO to the tank using the nuts from step 5 Take care not to damage the mounting studs Refer to wiring High Limit Switch diagram located on the inside of the upper control box cover and properly reconnect wire leads to new ECO 7 Verify proper ECO operation Mounting Stud Illustration 20 29 30 SERVICE PROCEDURE XV Heating Element Removal and Replacement Heating Element Removal and Replacement A WARNING 1 STOP DANGER Turn power OFF to water heater High voltage exposure To avoid hazard 2 Turn off cold water supply to heater Connect hose to drain to life or property be aUe power is turned spigot of water heater and route to an open drain Opena OFF to water heater while performing this nearby hot water faucet to vent heater for draining Open procedure drain spigot of water heater and allow heater to drain to a point below the element s 3 Close drain spigot and remove hose A WARNING 4 Remove access cover and insulation from lower control Heater components and stored water may be box Remove plastic cover from thermostat HOT when performing the following steps in this procedure Take necessary precaution to prevent personal injury 5 Disconnect wires from element terminals 6 Remove element from tank using 1 2 deep
13. contactors to energize or de energize all elements simultaneously In addition a separate high limit ECO control with manual reset is wired in series with the thermostat Both controls use a direct immersion bulb inserted into the tank to sense water temperature Immersion thermostat and high limit control are mounted to provide temperature adjustment and manual reset access from the exterior of the unit Surface Mounted Thermostats Surface mounted thermostats are mounted inside the lower control box in a bracket above each heating element The bracket holds the thermostat against the side of the tank responding to tank surface temperatures to sense a call for heat set point temperature and high limit ECO activation As each element is controlled by a dedicated thermostat it is possible to sequence the elements by varying the settings on the thermostat However 600V models with surface mounted thermostats operate contactors in the Line Voltage same manner as an immersion thermostat model only using surface thermostats to sense the call for heat S f operation for each is explained bel CIETE or gS equence of operation for each system is explained below i i l q p y p Fuse Block CEE q Terminal Block Sequence of Operation Immersion Thermostat Contactor Models ae ee en The system has two distinct circuits MJ 7 1 Power Circuit solid line D l i i Contactor 3 2 Control Circuit dotted line Coil
14. e in continuous operation resulting in overheated water limited only by the ECO located in the thermostat circuit Repeated actuation of the ECO usually is the result of a grounded heating element 3 Sediment Buildup Slow hot water recovery can usually be traced back to sediment or lime build up around heating element Sediment build up can also over time cause a dry fired element If a heating element is found to be inoperative it must be replaced Follow service procedure MCE XV on Page 30 The illustration below shows a common screw in type heating element identifying certain features commonly referred to throughout this manual Typical Direct Immersion Screw In Type Heating Element 1 2 Hex Zinc plated Copper Screw in Flange d a or Incoloy Sheath f J l a 0642 4500W 240V C02404524 8 Terminal Block Screw Element Rating Ink Stamped on Side of Terminal Block 13 TROUBLESHOOTING Quick Step Plan to Hot Water 1 STOP DANGER Turn power OFF to water heater A WARNING High voltage exposure Use caution when making voltage checks to avoid hazard to 2 Check all wire connections to insure that they are snug and life or property corrosion free 3 Reset high limit ECO Page 18 20 4 Check for inoperative heating element Page 15 5 Check line voltage Page 16 and internal fuses
15. ement The bracket holds the thermostat against the side of the tank responding to tank surface temperatures to sense a call for heat set point temperature and high limit ECO activation As each element has a dedicated thermostat for all models excluding 600V it is possible to sequence the elements by varying the settings on the thermostats of Manual ECO High Limit CI fd Reset Button gt KE Surface Mount T1 Combination Thermostat e A ECO high limit 89T Series Temperature Control Dial Py HOT ime Immersion Style Thermostat Control for Contactor Models as Direct The thermostat will complete control circuit Immersion gt lt amp f Bie voltage upon a call for heat Likewise the Bulb Ea E control will interrupt control circuit voltage when the water temperature is sufficient to Hy satisfy the adjustable temperature limit of S control p He m LJ L F Immersion Style High Limit ECO Control for Contactor Models The high limit ECO control will interrupt control circuit voltage causing the heater to shut down when the high temperature limit of the control is reached 196 F 4 F Once the cause for overheated water has been determined the control must be manually reset to re
16. erminals L1 and L3 oloo i i l oloalo Terminal Bloc 2 ECO high limit in thermostat is 2 closed so there is line voltage present at terminal L4 of rn thermostats and to one side of e ECO Closed each element a T Surface Mounted 2 a L Thermostat Heating Element Power to one side of element LEMEN 3 Water in the tank is cold so 3 all thermostats are closed at Thermostat closed terminal T2 calling for heat This at terminal T2 pes completes the circuit and allows em current to flow through heating elements 7 O F R n Xe ELEMENI 4 As each thermostat is satisfied it 4 opens at terminal T2 interrupting current flow through the es respective element The system ex is now in stand by mode waiting aia for the next call for heat a Q OS m Q B R l1 SEQUENCE OF OPERATION Sequence of Operation 6 Element Configuration Shown Line Voltage 600V Surface Mounted Thermostats w Contactors 9 Elements Possible The system has two distinct circuits Fuse Block 1 Power Circuit Line Voltage 600V Transformer 2 Control Circuit 120V 1 Line voltage is applied across terminals of fuse block o
17. ermostat dial see illustration 16 9 Once thermostat is removed disconnect wire leads to the thermostat NOTE It may be necessary to identify wires for proper reconnection to new thermostat 10 Refer to wiring diagram located on the inside of the upper control box cover and properly reconnect wire leads to new thermostat and remount control inside control box using screws from step 8 11 Replace control dial to stem of thermostat 12 Loosen ferrule nut of immersion bulb see illustration 17 Immersion Ferrule Bulb S s Nut C Tank Nut Illustration 17 SERVICE PROCEDURE XII Thermostat Removal and Replacement A WARNING High voltage exposure To avoid hazard to life or property be sure power is turned OFF to water heater while performing this procedure Immersion Thermostat Bulb ECO Location Control Thermostat Control Copper Capillary Mounting Screws Tube Located Under Thermostat Dial Immersion Thermostat Control Illustration 16 t v Copper Capillary Tube 13 Position tank nut at end of immersion bulb as shown in illustration 17 Insert immersion bulb into tank and tighten tank nut 14 Gently pull copper capillary tube to insure the immersion bulb is in a horizontal position as shown in illustration 17 and tighten ferrule nut 15 Resume water supply full tank and check for leaks 16 Be sure tank is full of water and resume power
18. ify proper heater operation N Tank Surface Proper Thermostat mounting flush with tank surface lt q Thermostat Dp ay a a Improper Thermostat mounting Thermostat not flush with tank surface a Thermostat Y o mounting bracket N H p SQ l Ron Front View Thermostat Mounting NF F Side View Side View Proper Thermostat Improper Thermostat Mounting Mounting 26 Immersion Thermostat Removal and Replacement 1 STOP DANGER Turn power OFF to water heater 2 Turn off cold water supply to heater Connect hose to drain spigot of water heater and route to an open drain Opena nearby hot water faucet to vent heater for draining Open drain spigot of water heater and allow water heater to drain to a point below the immersion bulb location see illustration 16 3 Close drain spigot and remove hose 4 Remove lower control box cover and insulation 5 Locate thermostat inside lower control box mounted to the right side of the box below the ECO control see illustration 16 6 Follow copper capillary tube from thermostat to the immersion bulb location and remove immersion bulb from tank using 11 16 wrench 7 Remove pull thermostat control dial from stem of thermostat 8 Remove the two thermostat mounting screws located under th
19. k thermostat s operation 6 Reset check ECO 7 Check contactor operation 1 Check heating element s 2 Clean or replace heating element s 3 Increase thermostat setting 4 Check thermostat s 5 Check contactor operation 6 Check all wire connection 7 Reduce demand 8 Replace with larger heater 9 Temper water to heater 10 Correct plumbing connections 1 Clean or replace heating elements 2 Check all wire connections 3 Check thermostat s 4 Check contactor operation 5 Verify element voltage and wattage rating 1 Check surface thermostat s mounting 2 Check heating element s 3 Adjust thermostat s to desired setting 4 Check thermostat s 5 Check ECO 1 Clean or replace heating element s 2 Verify line voltage to heater 1 Verify line voltage to heater 2 Replace contactor 3 Replace contactor 4 Check wire connections SERVICE PROCEDURE 2 II Page 17 4 I Page 15 5 VII IX Page 21 23 6 IV VI Page 18 20 7 X Page 24 25 1 I Page 15 2 XV Page 30 4 VII IX Page 21 23 5 X Page 24 25 1 XV Page 30 3 VII IX Page 21 23 4 X Page 24 25 5 See Page 8 1 XI Page 26 2 I Page 15 4 VII IX Page 21 23 5 TV VI Page 18 20 1 XV Page 30 2 II Page 16 1 II Page 16 SERVICE PROCEDURE I Heating Element Testing Test for Open or Burned Out Element 1 STOP DANGER Turn power OFF to water heater 2 Remove access c
20. l Box 31 Terminal Block Block A 32 Terminal Block End used for Block A 33 Terminal Block 2 Pole 34 Terminal Block 3 Pole 35 Screw 36 Fuse Block 2 Pole Class G 37 Fuse Block 3 Pole Class G 38 Fuse Block 3 Pole Class J 39 Contactor 3 Pole 40 Contactor 4 Pole 41 Screw 42 Contactor Coil 43 Fuse Class G 44 Fuse Class J 45 Fuse Class J 46 Ground Lug Small 47 Ground Lug Large 48 Screw 49 3 4 NPT Plug 50 Transformer 120V Term Definition Unit of Measure Voltage Electrical potential Volts Current Rate of voltage flow Amperes amp Resistance Ability of a device to dissipate power irreversibly Ohms Energy Ability to do work kW hr Joule Power Energy per unit of time Watts kW VA One Kilowatt 1kW 1 000 Watts 3 412 BTU DC Direct Current AC Alternating Current Hz Hertz F Degrees Fahrenheit C Degree Centigrade BTUH British Thermal Units per Hour PSI Pounds per Square Inch GPM Gallons per Minute GPH Gallons per Hour ECO Energy Cut Off NPT National Pipe Thread ASME American Society of Mechanical Engineers 33 34 NOTES NOTES 35 Madison Wisconsin For U S and Canada field service contact your professional installer or local Bock Water Heaters sales representative Sales 608 227 3311 Fax 608 327 3311 Application amp Sizing 608 227 3311 Fax 608 327 3311 Technical Support 888 784 8322 Fax 610 683 9208 Warranty 608 227 3319
21. ltage IS present thermostat is calling for heat go to step 8 x OO A R CY 8 Check across element terminals see illustration 10 A Rated voltage NOT present check wire connections from thermostat to element ELEMENT B Rated voltage IS present repeat element testing see Page 15 Illustration 10 Water in Tank is Above Thermostat Settings 1 This procedure assumes line voltage ECO and elements are in working order 2 Turn power ON to water heater 3 Set multi meter to Volts AC 4 See illustration 9 check across terminals L4 and T2 of thermostat A Rated voltage IS present replace thermostat B Rated voltage NOT present thermostat is okay C Lower than rated voltage IS present recheck for grounded element see Page 15 ZA a2 SERVICE PROCEDURE VIII Thermostat Testinc 600V Surface Mounted Thermostat Models Operation Testing A WARNING High voltage exposure To avoid hazard to Water in Tank is Cold with Power ON life or property use extreme caution when making voltage checks 1 This procedure assumes line voltage ECO transformer thermostat and elements are in working order 2 Turn power OFF to water heater 3 Remove access cover from lower control box Remove insulation from inside of control box 4 Using a phillips head screwdriver disconnect the wire lead at terminal 2 of the thermostat Only check one thermostat at a time to insu
22. ned to aid service and maintenance professionals in the function proper diagnosis and repair of Bock Water Heaters Commercial Electric Water Heaters The text and illustrations in this manual provide step by step instructions to facilitate proper operation and troubleshooting procedures Contact Bock Water Heaters Technical Support immediately if diagnosis cannot be made using the methods described in this service manual Tools Multi Meter Philips Head Screw Driver 1 1 2 Deep Well Socket Common Screw Driver 1 1 16 Deep Well Socket Thermometer 1 4 Nut Driver Drain Hose Other hand tools pipe wrench channel locks pliers common amp needle nose wire cutters wire strippers allen wrench set flash light OB 1 2 Oc s ATER HEATERS J Commercial Electric General Information Bock Waters Heaters Commercial Electric water heaters can be manufacturered with a choice between two different types of thermostat control options as follows surface Mounted Thermostats Immersion Thermostat contactor models The model number is coded to identify the specific thermostat control system used for a particular unit Below is a typical model number and coded definitions 50 SF 6 208 240 _ kW Rating CF Contactor w Fuse Immersion Thermostat SF Surface Thermostat w Fuse Tank Capacity MFG FOR BOCK WATER HEATERS INC 110 S DICKINSON MADISON WI 53703 Model Number Model No 50SF 6 208 240
23. or feel a small click the switch has actuated 2 Use caution and turn power on to water heater and observe heating cycle following the high limit heating cycle flow chart High Limit Control Continuity Testing for Contactor Models 1 STOP DANGER Turn power OFF to water heater 2 Water temperature must be below 196 F 4 3 Remove high limit switch from control panel It is not necessary to remove immersion bulb from tank at this time See general controls layout on Page 4 for location 4 Disconnect wire leads to high limit control during this test 5 Depress reset buttons to insure switch contacts are closed 6 Set multi meter to ohms setting Check continuity through circuit A and B as showing in the illustrations below A Continuity IS present switch is okay B Continuity NOT present replace switch SERVICE PROCEDURE VI High Limit ECO Testina A WARNING High voltage exposure To avoid hazard to life or property be sure power is turned OFF to water heater while performing this procedure Observe heating cycle Is water temperature Does switch open over 196 F High Limit Heating Cycle Flow Chart NOTE Disconnect Circuit A Continuity Testin 20 O Wire Leads to Control Circui
24. over from lower control box Remove insulation from inside of control box 3 Disconnect wires from heating element 4 Set multi meter to ohms setting 5 Touch probes of multi meter to screw terminals of heating element see illustration 1 6 Reading should be 12 8 ohms 6 for a 240 volt 4500 watt element see table below for other elements Ohms Volts Watts A reading outside the range using the formula above 6 indicates a bad element and the element must be replaced Ohms of Electrical Resistance for Commonly Used Elements Voltage Rating of Element Element Wattage 208 240 480 2000 21 6 28 8 115 2 3000 14 4 19 2 76 8 4000 10 8 14 4 57 6 4500 9 6 12 8 51 2 5000 8 7 11 5 46 1 6000 7 2 9 6 38 4 Test for Grounded Heating Element Damaged Heating Element with Short Circuit to Ground 1 STOP DANGER Turn power OFF to water heater 2 Remove access cover from lower control box Remove insulation from inside of control box 3 Disconnect wires from heating element 4 Set multi meter to ohms setting 5 Touch one probe of multi meter to either screw terminal of heating element and the other on the element flange see illustration 2 There should be no reading on the ohm meter Any reading indicates a grounded element and the element must be replaced Repeat this step for the other screw terminal A WARNING High voltage exposure To avoid hazard to life or property be sure
25. power is turned OFF to water heater while performing this procedure NOTE Disconnect Element Wires Element Screw Terminals Illustration 1 Q Disconnect J Element Wires S Element Flange gt Element Screw Terminal Illustration 2 SERVICE PROCEDURE II Line Voltage Testing Line Voltage Testing A WARNING Line voltage single phase or three phase will connect to a High voltage exposure To avoid hazard to terminal block or directly to a fuse block located inside the life or property use extreme caution when control panel making voltage checks Determine heaters voltage and phase by referring to the rating plate located on the front of the water heater Apply the appropriate phase procedure below to determine if proper line Line voltage from Line voltage from voltage is present service panel OR service panel connected to Terminal block connected to Fuse block Single Phase Line Voltage Testing Ol neater obtenar 1 STOP DANGER Turn power OFF to water heater 2 Open upper control panel door TATTA I z 3 Determine connection point for line voltage from service PNE E e CO IDLoN logal O panel terminal block or fuse block
26. r a terminal block Line voltage continues down and connects to terminals L1 L2 and L3 of one or more contactors A Contactor is open no call for heat so there is no voltage across terminals T1 T2 and T3 of contactor B The contactor is controlled by the control circuit consisting of the surface mounted thermostat ECO high limit and contactor coil Contactor 2 When the thermostat calls for heat contacts close inside BK w the thermostat completing the circuit through the ECO and energizing the contactor coil 3 The energized contactor coil causes the contactor to close BK energizing the elements from terminals T1 T2 and T3 of the BK oK contactor R 4 When the temperature setting of the thermostat is reached BK the contacts in the thermostat open This interrupts current flow through the control circuit de energizing the contactor coil E E ae High Limit 5 The de energized contactor coil causes the contactor to W open interrupting current flow through the elements The O heater is now in stand by waiting for the next call for heat 6 Notice in the wiring diagram at right that each row of QO Al elements is equipped with a surface mounted thermostat x x CO on the highest element in the row These thermostats are x tHe individually wired in series to the contactor whose line m voltage corresponds to the same row of elements Each eY amp thermostat and contactor combination are
27. r to wiring diagram located on the inside of the upper control box cover and properly reconnect wire leads to new ECO control and remount control inside control box using screws from step 7 10 Loosen ferrule nut of immersion bulb see illustration 19 Immersion Ferrule B Nut ulb y U Copper Capillary Tube Tank Nut Illustration 19 11 Position tank nut at end of immersion bulb as shown in illustration 19 Insert immersion bulb into tank and tighten tank nut 12 Gently pull copper capillary tube to insure the immersion bulb is in a horizontal position as shown in illustration 19 and tighten ferrule nut 13 Resume water supply full tank and check for leaks 14 Be sure tank is full of water and resume power supply to water heater Verify proper ECO operation 28 SERVICE PROCEDURE XIV 600V Model High Limit ECO Control Removal and Replacement 600V Surface Thermostat Model High Limit ECO Control Removal and Replacement A WARNING High voltage exposure To avoid hazard 1 STOP DANGER Turn power OFF to water heater to life or property be sure power is turned OFF to water heater while performing this 2 Remove lower control box cover and insulation procedure 3 Locate high limit switch ECO mounted to the tank above the element spuds see illustration 20 4 Disconnect wire leads to the ECO NOTE It may be necessary to identify wires for proper re
28. re wires are correctly reinstalled upon completion Mark wires if necessary for reinstallation 5 Set multi meter to check continuity 6 Use caution and check continuity across terminals 1 and 2 for all thermostats see illustration 11 A Continuity NOT present replace thermostat Illustration 11 B Continuity IS present thermostat is okay Water in Tank is Above Thermostat Settings 1 This procedure assumes line voltage ECO thermostat transformer and elements are in working order 2 Turn power OFF to water heater 3 Remove access cover from lower control box Remove insulation from inside of control box 4 Using a phillips head screwdriver disconnect the wire lead at terminal 2 of the thermostat Only check one thermostat at a time to insure wires are correctly reinstalled upon completion Mark wires if necessary for reinstallation 5 Set multi meter to check continuity 6 Use caution and check continuity across terminals 1 and 2 for all thermostats see illustration 11 A Continuity NOT present replace thermostat B Continuity IS present thermostat is okay SERVICE PROCEDURE IX Thermostat Testinc Immersion Thermostat Operation Testing A WARNING a High voltage exposure To avoid hazard to Thermostat Specification life or property use extreme caution when Calibration 184 F 176 F makinc Max Differential 6 F voltage checks Opera
29. store normal operation Direct Immersion Bulb GENERAL INFORMATION Surface Mounted Thermostats w Contactors for 600V Models 600V models use contactors to deliver line voltage to the heating elements However rather than the immersion type high limit and thermostat devices surface mounted thermostats are used to operate the control circuit of the water heater Surface Mounted Thermostat Surface Mounted 59T Series ECO High Limit I pal lea 40A 120 277 VAC 25A 480 600 VAC 125 VA PT DTY 120 480 VAC Temperature Control Dial Manual Reset Button GENERAL INFORMATION Contactor Contactor operation is achieved by energizing an operating coil in response to a call for heat from the immersion thermostat Upon a call for heat one or more contactors will energize all heating elements simultaneously The operating coils are voltage specific When contactor replacement is required be sure to order the proper operating coil based on the voltage rating found on the rating plate located on the front of the water heater Terminal Connections of Contactor Operating Coil Terminal Connections to the Fuse Block and or Terminal Block Terminal Connections to the Heating Elements Direct Immersion Screw in Type Heating Element 1 Hex Zinc plated Copper Screw in Flange Termin
30. supply to water heater Verify proper thermostat operation 21 SERVICE PROCEDURE XIII Contactor Model High Limit ECO Control Removal and Replacement Contactor Model High Limit ECO Control Removal and Replacement A WARNING High voltage exposure To avoid hazard 1 STOP DANGER Turn power OFF to water heater to life or property be sure power is turned OFF to water heater while performing this 2 Turn off cold water supply to heater Connect hose to drain PPY procedure spigot of water heater and route to an open drain Open a nearby hot water faucet to vent heater for draining Open drain spigot of water heater and allow water heater to drain to a point below the immersion bulb location see illustration 18 3 Close drain spigot and remove hose 4 Remove lower control box cover and insulation 5 Locate ECO Control inside lower control box mounted to the right side of the box above the thermostat control see illustration 18 6 Follow copper capillary tube from ECO Control to the immersion bulb location and remove immersion bulb from tank using ECO 11 16 wrench Immersion Bulb Location BGO 7 Remove the two ECO control mounting screws located outside Control the lower control box Copper Capillary Thermostat 8 Once ECO control is removed disconnect wire leads to the Tube Control control NOTE It may be necessary to identify wires for proper reconnection to new control 9 Refe
31. t B Continuity Testin SERVICE PROCEDURE VII Thermostat Testinc Surface Mounted Thermostat Operation Testing NOT including 600V A WARNING High voltage exposure To avoid hazard to Water in Tank is Cold with Power ON life or property use extreme caution when making voltage checks aa Lies it Te it e TB 1 This procedure assumes line voltage ECO and elements are in working order 2 Turn power OFF to water heater We 3 Remove access cover from lower control box s 5 5 x r s T2 Remove insulation from inside of control box Remove plastic cover from thermostat N O 4 Turn power ON to water heater Ol 5 Set multi meter to Volts AC 6 Use caution and check voltage across terminals L1 and L3 ELEMENT ELEMENT for all thermostats see illustration 8 Illustration 8 Illustration 9 A Rated voltage NOT present check fuses and or line voltage B Rated voltage IS present proceed to step 7 25 7 oy oT 7 Check across terminals L4 and T2 of thermostat see illustration 9 F P T2 A Rated voltage NOT present recheck ECO If ECO is okay replace thermostat C E P B Rated vo
32. ting Range 80 F to 180 F Providing the water temperature in tank is within the operating range of the thermostat checking thermostat operation can be as simple as rotating the SIIS S thermostat dial and listening to the contactor s to see if they respond to a call 1 Lo 13 for heat Use caution and turn power ON and rotate the thermostat dial to call for heat With water temperature below the thermostat setting the contactor s close With the contacts closed use caution and check for rated voltage across lower terminals of contactor s see illustration 12 If rated voltage is present the thermostat is calling for heat d gt Rotate thermostat dial to the minimum setting With water temperature above Giedvoinge across the thermostat setting the contactor s will open With the contacts open lower terminals of contactor s voltage should not be present at lower terminals of contactor s Illustration 12 Thermostat Control Continuity Testing 1 This procedure assumes line voltage ECO and contactor s are in working order 2 Turn power OFF to water heater 3 Remove access cover from lower control box Remove insulation from inside of control box 4 Locate thermostat control see general controls layout on Page 4 and remove wire leads to control screw terminals 5 Water temperature in tank m
33. ting plate located on the front of the water heater In addition debris between the contact plates will cause noisy operation Contactor Operating Coils Contactor operation is achieved by energizing an operating coil in response to a call for heat from the thermostat There are three different operating coils used depending on voltage rating of the water heater as follows Description Color Code 208 240 Volt Coil Green 277 Volt Coil Blue 480 Volt Coil Black All the coils have a color code for visual confirmation In addition the 277 and 480 volt coils are labeled with voltage rating for proper identification All contactors supplied for replacement are equipped with the 208 240 volt operating coil By removing the rear mounting plate of the contactor the operating coils can be changed based on desired service voltage When contactor replacement is required be sure to order the proper operating coil base on the voltage rating found on the rating plate located on the front of the water heater Rear Mounting Plate Operating Coil Color Code Location Identification Label Location 24 Contactor Operation Testing continued This procedure assumes control circuit is operating correctly Providing the water temperature in tank is within the operating range of the thermostat checking contactor operating can be as simple as rotating the thermostat dial and listening to the contactor s to see if the
34. ust be within operating range of thermostat for this test If above or below it will be necessary to drain tank and remove thermostat immersion bulb from tank to warm or cool the bulb to be within operating range of thermostat Thermostat Immersion Bulb 6 Set multi meter to the Ohms setting pa 7 Rotate thermostat dial to highest setting L 8 Check across screw terminals of control see illustration 13 Thermostat A Continuity NOT present replace thermostat B Continuity IS present proceed to step 9 9 Rotate thermostat dial to lowest setting 10 Check across screw terminals of control see illustration 13 A Continuity NOT present thermostat is okay B Continuity IS present replace thermostat NOTE Disconnect Wire Leads to Control Screw Terminals Illustration 13 2 SERVICE PROCEDURE X Contactor Testina Contactor Operation Testing A WARNING High voltage exposure To avoid hazard to life or property use extreme caution when making voltage checks Noisy Contactor Noisy or chattering contactor operation in most cases is due to voltage variations being supplied to the water heater Extended periods of voltage variations will cause damage to the operating coil of the contactor causing noisy operation Determine that service voltage to the unit meets the electrical requirements per the ra
35. water heater resume water supply refill water heater with water and check for leaks 8 To resume operation BE SURE TANK IS FULL OF WATER and turn power ON to water heater Anode Rod Locations 31 GENERIC PARTS LIST TERMINAL BLOCKS FUSE BLOCKS CONTACTORS FUSES GROUND LUGS CC 45 CONTACTOR COILS a s N 46 Ly yy A g 2 35 35 42 TRANSFORMER 600V ONLY 3 NS 3A 4 a ae a 4A a orn 29 Ps ye Wo A 5 ee 28 49 i G Pa Uti 9 pa Paar 7 tT 5A e2 GENERIC PARTS LIST Item Description 1 Anode Rod 2 Hot Water Outlet Nipple 3 T amp P Nipple 3A T amp P Coupling T amp P Relief Valve 5 High Limit Switch 5A Surface High Limit Switch 6 Hex Nut 7 Lock Washer 8 Screw 9 High Limit Spacer 10 Cleanout O Ring 10A Cleanout Gasket ASME 11 Cleanout Cover 11A Cleanout Cover ASME 12 Cleanout Cover Screw 12A Cleanout Cover Screw ASME 13 Cleanout Access Cover 14 Brass Drain Valve 15 Escutcheon 16 Drain Extender 17 Thermostat Dial 18 Screw 19 Immersion Thermostat 20 Heating Element 21 Surface Thermostat Bracket 22 Surface Thermostat 23 Surface Thermostat Cover Glossary of Terms Item Description 24 Lower Control Box Cover 25 Heating Element Plug 26 Heating Element Gasket 27 Cold Water Inlet Nipple 28 Plastic Snap Bushing 29 Lower Control Box 30 Upper Contro
36. well socket or appropriate wrench Unscrew element counter clockwise to remove from tank 7 Be sure to remove old element gasket from the tank It is recommended to replace the gasket with a new one 8 Check new element terminal block for proper electrical rating NOTE Some elements have dual ratings be sure to check all surfaces of the element terminal block see illustration 21 9 Apply new element gasket to the new element Be sure gasket is seated flat against element flange without rolls or gaps see illustration 21 10 Clean any debris from element fitting on tank 11 Thread new element clockwise into tank Tighten element using 1 2 deep well socket or appropriate wrench Do not over tighten over tightening may damage element gasket 12 Reconnect wires to element Be sure connections are snug and corrosion free Do not over right as that may damage terminal block 13 Resume water supply to heater Be sure tank is full of water and check for leaks 14 Reinstall plastic thermostat protector s 15 Reinstall insulation and control box cover 16 To resume operation BE SURE TANK IS FULL OF WATER and restore power to water heater Verify proper heater operation Element Rating Example 4500 Watt 240 Volt Element Flange Element Gasket Seated Flat Against Element Flange Without Rolls or Gaps 52 Sa Date Code 0642 4500W 240V RC02404524
37. wired to the K i 59T 46 ECO in parallel This allows for each row of elements to RA be powered ON independent of the other element rows BK However the ECO is wired in series so that voltage can be interrupted to the entire control circuit if the ECO senses that the tank water has become overheated R Heating Elements 12 TROUBLESHOOTING The most common cause of improper electric water heater operation can be linked to heating element failure When troubleshooting an electric water heater with the incidence of no hot water or insufficient amount of hot water it is always a good idea to check the heating elements first following the procedure on Page 15 Common heating element failures are 1 Dry Firing Elements may be partially submerged in water or most likely completely exposed with no water in the tank at all In open air an energized element dry fired will become completely inoperable within seconds In some cases sediment or lime build up around an element can eventually cause an air pocket resulting in a dry fired element When element replacement is required be sure tank is full of water prior to energizing the water heater 2 Grounded Element In most cases an element with a short circuit to ground will cause the circuit breaker in the service panel to open or shut off In some cases there may not be enough current draw for the circuit breaker to open This will allow the heating element to b
38. y respond to a call for heat 1 Turn power ON and rotate thermostat dial to the maximum setting With water temperature in tank below the thermostat setting the contactor s will close With the contacts closed check for line voltage across operating coil terminals see illustration 14 A Line voltage IS present go to step 2 B Line voltage NOT present verify control circuit operation 2 Check for rated voltage across lower terminals of contactor s see illustration 15 A Rated voltage IS present go to step 3 B Rated voltage NOT present replace contactor 3 Rotate thermostat dial to the minimum setting With water temperature in tank above thermostat setting the contactor s will open With the contacts open voltage should not be present at lower terminals of contactor s 4 Check for line voltage across operating coil terminals see illustration 14 A Line voltage IS present verify control circuit operation B Line voltage NOT present go to step 5 5 Check for rated voltage across lower terminals of contactor s see illustration 15 A Rated voltage IS present replace contactor B Rated voltage NOT present contactor is okay SERVICE PROCEDURE X Contactor Testina A WARNING High voltage exposure To avoid hazard to life or property use extreme caution when making voltage checks Illustration 14
39. z a Contactor eee 1 Line voltage is applied across terminals of fuse block or a Lo terminal block Line voltage continues down and connects to terminals L1 L2 and L3 of one or more contactors ECO High Limit A Contactor is open no call for heat so there is no voltage across terminals T1 T2 and T3 of contactor O T stat B The contactor is controlled by the control circuit nore consisting of the immersion thermostat ECO high limit and contactor coil 2 When the thermostat calls for heat contacts close inside the thermostat completing the circuit through the ECO and energizing the contactor coil 3 The energized contactor coil causes the contactor to close energizing the elements from terminals T1 T2 and T3 of the contactor 4 When the temperature setting of the thermostat is reached the contacts in the thermostat open This interrupts current flow through the control circuit de energizing the contactor coil 5 The de energized contactor coil causes the contactor to open interrupting current flow through the elements The heater is now in stand by waiting for the next call for heat Heating Elements 10 SEQUENCE OF OPERATION Sequence of Operation Line Voltage Surface Mounted Thermostats o 1 Line voltage is applied across terminals of fuse block or a terminal Fuse Block block Line voltage continues down and connects to surface mounted thermostats at t
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