Home

Tankless Gas Troubleshooting Manual SVC 820

1. SVC 820 Tankless Gas Troubleshooting Manual Page 99 Ambient Thermistor RTG64DV RTG84DV RTG95DV CG CF kQ V C PF kQ V CUBES kQ V 25 13 00 87 7437 4 746 20 68 00 10 3839 3 442 65 149 00 2 1687 1 579 24 11 20 82 9816 4 732 21 69 80 9 9767 3 399 66 150 80 2 1044 1 546 23 9 40 78 5129 4 718 22 71 60 9 5880 3 355 67 152 60 2 0424 1 515 22 7 60 74 3177 4 703 23 73 40 9 2169 3 311 68 154 40 1 9826 1 483 21 5 80 70 3773 4 687 24 75 20 8 8626 3 267 69 156 20 1 9248 1 453 20 4 00 66 6745 4 671 25 77 00 8 5241 3 223 70 158 00 1 8691 1 423 19 2 20 63 1933 4 654 26 78 80 8 2007 3 178 71 159 80 1 8153 1 393 18 0 40 59 9192 4 636 27 80 60 7 8915 3 134 72 161 60 1 7633 1 364 17 1 40 56 8382 4 618 28 82 40 7 5960 3 089 73 163 40 1 7131 1 336 16 3 20 53 9378 4 599 29 84 20 7 3134 3 044 74 165 20 1 6646 1 308 15 5 00 51 2062 4 580 30 86 00 7 0431 2 999 75 167 00 1 6178 1 280 14 6 80 48 6325 4 559 31 87 80 6 7844 2 954 76 168 80 1 5725 1 253 13 8 60 46 2064 4 538 32 89 60 6 5368 2 909 77 170 60 1 5288 1 22
2. 7 L A ee T KT cm L B5 jo H he NY NR 12 IA H n foe NG Bottom of Unit 4 Turn power OFF Remove and reinsert connector G on Turn power OFF Remove 3 screws for Control Board Control Board Attempt to operate unit again IF 10 mounting bracket Remove connectors M T amp G Warning Code does NOT display unit had a loose Pull PCB out of way to access Blower Motor connection Remove 3 screws holding Blower Motor in place Clean Blower Motor and reassemble unit Attempt to operate l l Locate Min amp Max buttons on Control Board unit again IF 10 Warning Code does NOT display l Continue to diagnostic chart on next page Blower Motor needed to be cleaned SVC 820 Tankless Gas Troubleshooting Manual Page 31 10 Warning Code Diagnostic Chart Remove and reinsert connector G at Control Board Test DC voltage across black and red Is the DC voltage OK Attempt to operate unit again wires on connector G NO IF unit continues to display Error Code 10 144 192 DC VOLTS Replace Control Board YES Press and hold down MAX button on Control Board to activate the Blower Motor While Blower Motor is running test DC voltage across black and white wires on connector G 12 18 DC VOLTS Remove and reinsert connector G at Is the DC voltage Control Board OK Attempt to operat
3. Water flows thru the Water Flow Sensor Minimum flow rate of 4 GPM to activate 9 35 AT Control Board senses the flow rate has reached a minimum demand of 4 GPM 35 AT Control Board is the brains of the machine and controls all input and actions during sequence of operations Blower Motor conducts a pre purge Pre purge is designed to verify we have a clear and clean vent and supply oxygen to burner for proper ignition The Proportional Gas Flow Regulator allows the gas to flow to the main burner Proportional Gas Flow Regulator initially opens to 7596 of BTU input Simultaneously the Igniter Rod sparks and ignites the main burner The Igniter Rod ignites the fuel in the main burner area All burners will fire initially After ignition the Flame Rods sense and monitor the flame and ensure proper combustion The purpose of the flame rods is to verify flame and proper combustion In the event of flame failure or improper combustion the unit will go into an error code The In Use Indicator on the remote control turns ON Red and the Priority Indicator is Green multiple remote controls Main burner is now lit The PCB goes thru a series of calculations input sensing to balance out the cold water temperature the thermostat setting the hot outlet temperature and the BTU required to heat the water The Proportional Gas Flow Regulator continuously adjusts
4. 20 Seconds Buttons 31 32 HE Thermistor 33 Outlet Thermistor 34 Ambient Thermistor Inlet Thermistor Thermistors Check 90 gt 12 seconds 72 5 seconds Gas Control Valve amp Igniter Rod On Detect Flame Igniter Rod Off 1 2 Ignition Attempt 11 2 Ignition Attempts Next Page Imperfect Combustion Alarm No Decrease of Fan Motor Ventilation 10 Warning Code Flashing Flame Failure 2 Monitoring Sequence while unit is in i operation Attempt to Re lgnite Yes 1 2 Ignition Attempts cg A o Condensation Not Draining 29 Condensing Only Hot Water gt 207 Degrees F for more than 15 seconds Heat Exchanger gt 207 Degrees F for m ore than 15 seconds Outlet water temperature too high Trouble with Thermistor s Heat Exchanger Outlet Temp Too Low Gas Control Valve PGFR Gas Control Valve Ambient Thermistor Next Page 5 C Communication Blower Motor Flame Rod Current Not Detected Trouble Remote Control Blower Motor Water Control Body Bypass Assembly Outlet Thermistor Heat Exchanger Inlet Thermistor Thermistor Close Hot Water Tap Gas Control Valve Off Detect Flame Checking 80 Gas Control Valve Yes 8 Seconds Later 51 Gas Control Valve Blower Motor Unit in Stand By mode SVC 820 Tankless Gas Troubleshooting Ma
5. 62 Check the resistance across 2 white wires on bottom Molex 7k 23K Ohms SVC 820 Tankless Gas Troubleshooting Manual Page 63 32 Error Code Diagnostic Chart Is the resistance to the Heat Exchanger Thermistor OK NO YES Remove Molex from connector R at Control Board Check continuity from black 3 wire at Molex connector R and black wire at Yellow Molex located behind Control Board Check continuity from Yellow 5 wire at Molex connector R and Yellow wire at Yellow Molex located behind Control Board Is the continuity across all wires OK YES Attempt to operate unit again If the unit malfunctions due to an Error Code 32 Replace Control Board Clean Scale Build Up on Heat Exchanger Thermistor Retest Thermistor IF test OK the water heater appears to be normal Attempt to operate unit again IF resistance NOT OK Replace Heat Exchanger Thermistor Replace wiring harness for Connector R on Control Board 63 64 Page SVC 820 Tankless Gas Troubleshooting Manual 33 Error Code Explanation Outlet Thermistor malfunction Diagnostic Checks e Outlet Thermistor OUTLET THERMISTOR DIAGNOSTICS Turn power OFF Remove connector R on Control Board Measure resistance between Black 3 amp Red 4 wires 7K 23K Ohms IF OK attempt to operate unit again IF 33 Error Code does NOT display unit had a loose connection Molex Conne
6. Turn power OFF Remove connector R on Control Board Measure resistance between Black 3 amp white 6 wires 7K 23K Ohms IF OK attempt to operate unit again IF 31 Error Code does NOT display you had a loose connection Molex for Inlet Thermistor located near the Blower i Motor Turn power OFF Remove 3 screws for Control Board mounting bracket Remove connectors M T amp G Pull Control Board out of way to access WHITE Molex Connectors EN zr a j M he aj NT en S Ss Separate top and bottom of WHITE Molex for the Inlet Thermistor Top of Molex has 2 black wires and 1 white wire Bottom of Molex has 2 white wires Continue to Diagnostic Chart on next page Inlet Thermistor SVC 820 Tankless Gas Troubleshooting Manual Page 61 31 Error Code Diagnostic Chart Clean scale build up on Inlet Thermistor Retest Thermistor Check the resistance across 2 white wires Is the resistance to the Inlet Thermistor OK IF tests OK the water heater appears to be on bottom Molex NO normal Attempt to operate unit again 7K 23K Ohms IF resistance NOT OK Replace Inlet Thermistor YES Remove Molex from connector R at Control Board Check continuity from black 3 wire at Molex connector R and black wires at White Molex located behind Control Board Check continuity from white H6 wire at Molex connector R and white wire at White Molex located behind Control Boar
7. 23K Ohms Replace Outlet Thermistor YES Remove Molex from connector R at Control Board Check continuity from black 3 wire at Molex connector R and black wires on black Molex located behind Control Board Check continuity from red 4 wire at Molex connector R and red wire on black Molex located behind Control Board Replace wiring harness for connector R on Control Board Is the continuity across all wires OK NO YES Attempt to operate unit again If the unit malfunctions due to an Error Code 16 Go to Error Code 66 for Water Bypass Valve diagnostics 55 56 56 Page SVC 820 Tankless Gas Troubleshooting Manual 24 Error Code Explanation Remote Control buttons were depressed for more than 20 seconds IF you were manually holding down any Remote Control buttons for more than 20 seconds release the buttons and NO Error Code will be displayed Unit will operate normally IF error code 24 is still displayed after releasing Remote Control buttons continue to Remote Control diagnostics Diagnostic Checks e Remote Control REMOTE CONTROL DIAGNOSTICS Remote Control Wiring Terminals Hot Water Outlet Turn power OFF Remove and reconnect Remote Control wiring terminals at bottom of unit Attempt to operate unit again IF 24 Error Code does NOT display unit had a Visually inspect Remote Control wiring for damaged or loose terminals loose connection IF 24 Error Code IS
8. 4 542 27 80 60 4 5775 2 467 72 161 60 0 8231 0 745 17 1 40 43 8917 4 516 28 82 40 4 3818 2 412 73 163 40 0 7964 0 724 16 3 20 41 3370 4 490 29 84 20 4 1957 2 358 74 165 20 0 7706 0 704 15 5 00 38 9491 4 462 30 86 00 4 0186 2 305 75 167 00 0 7458 0 685 14 6 80 36 7159 4 433 31 87 80 3 8500 2 251 76 168 80 0 7220 0 666 13 8 60 34 6266 4 402 32 89 60 3 6896 2 199 77 170 60 0 6990 0 647 12 10 40 32 6707 4 371 33 91 40 3 5369 2 147 78 172 40 0 6769 0 629 11 12 20 30 8391 4 339 34 93 20 3 3914 2 096 79 174 20 0 6557 0 612 10 14 00 29 1229 4 305 35 95 00 3 2528 2 045 80 176 00 0 6352 0 595 9 15 80 27 5141 4 271 36 96 80 3 1207 1 995 81 177 80 0 6154 0 579 8 17 60 26 0053 4 235 37 98 60 2 9947 1 946 82 179 60 0 5964 0 563 7 19 40 24 5897 4 198 38 100 40 2 8746 1 898 83 181 40 0 5781 0 548 6 21 20 23 2609 4 160 39 102 20 2 7600 1 850 84 183 20 0 5604 0 533 5 23 00 22 0130 4 120 40 104 00 2 6507 1 803 85 185 00 0 5433 0 518 4 24 80 20 8406 4 080 41 105 80 2 5464 1 757 86 186 80 0 5269 0 504 3 26 60 19 7387 4 038 42 107 60 2 4468 1 712 87 188 60 0 5111 0 490 2 28 40 18 7025 3 996 43 109 40 2 3517 1 667 88 190 40 0 4958 0 477 1 30 20 17 7277 3 952 44 111 20 2 2609 1 624 89 192 20 0 4810 0
9. SVC 820 Tankless Gas Troubleshooting Manual Page 29 10 Warning Code Explanation The Blower Motor is not creating enough ventilation The system passed the pre purge cycle but detects vent blockage during normal operation The unit will continue to operate but may eventually shut down with Error Code 99 First check your GAS SUPPLY amp VENTING the most common causes for Error Code 10 Diagnostic Checks e GAS SUPPLY amp VENTING e Blower Motor GAS SUPPLY amp VENTING REFER TO USE amp CARE MANUAL Make sure you have sufficient fuel for the unit to operate properly 1 AE oU ad Gas Type LP or Natural Gas Gas Pressure Gas Pipe Size Gas Flex Line Not To Exceed 36 In Length has the proper ID Inside Diameter and correct BTU rating Gas Regulator Gas Shut Off Valves Air In Gas Line Visually inspect venting for possible blockage and or recirculation of exhaust 1 ey ur do IN D P A a Approved Venting Materials Approved Vent Terminations Vent Lengths Location Of Vent Termination Recirculation of exhaust Blocked Venting Venting Not Sealed Properly 29 30 30 Page SVC 820 Tankless Gas Troubleshooting Manual BLOWER MOTOR DIAGNOSTICS
10. 00 31 1082 4 344 40 104 00 4 8970 2 551 85 185 00 1 2268 1 035 4 24 80 29 6561 4 316 41 105 80 4 7282 2 507 86 186 80 1 1943 1 013 3 26 60 28 2819 4 287 42 107 60 4 5663 2 464 87 188 60 1 1629 0 992 2 28 40 26 9807 4 258 43 109 40 4 4109 2 421 88 190 40 1 1324 0 971 1 30 20 25 7484 4 228 44 111 20 4 2617 2 378 89 192 20 1 1029 0 950 0 32 00 24 5807 4 197 45 113 00 4 1185 2 335 90 194 00 1 0744 0 930 1 33 80 23 4739 4 166 46 114 80 3 9809 2 293 91 195 80 1 0467 0 911 2 35 60 22 4245 4 134 47 116 60 3 8487 2 251 92 197 60 1 0199 0 892 3 37 40 21 4291 4 101 48 118 40 3 7217 2 210 93 199 40 0 9939 0 873 4 39 20 20 4846 4 067 49 120 20 3 5996 2 169 94 201 20 0 9687 0 854 5 41 00 19 5880 4 032 50 122 00 3 4823 2 128 95 203 00 0 9443 0 837 6 42 80 18 7367 3 997 51 123 80 3 3695 2 088 96 204 80 0 9207 0 819 7 44 60 17 9281 3 961 52 125 60 3 2610 2 048 97 206 60 0 8977 0 802 8 46 40 17 1598 3 925 53 127 40 3 1566 2 009 98 208 40 0 8754 0 785 9 48 20 16 4295 3 888 54 129 20 3 0562 1 970 99 210 20 0 8538 0 769 10 50 00 15 7351 3 850 55 131 00 2 9595 1 932 100 212 00 0 8329 0 753 11 51 80 15 0746 3 812 56 132 80 2 8665 1 894 12 53 60 14 4462 3 773 57 134 60 2 7769 1 857 13 55 40 13 8482 3 733 58 136 40 2 6906 1 820 14 57 20
11. 123 80 3 3695 2 088 96 204 80 0 9207 0 819 7 44 60 17 9281 3 961 52 125 60 3 2610 2 048 97 206 60 0 8977 0 802 8 46 40 17 1598 3 925 53 127 40 3 1566 2 009 98 208 40 0 8754 0 785 9 48 20 16 4295 3 888 54 129 20 3 0562 1 970 99 210 20 0 8538 0 769 10 50 00 15 7351 3 850 55 131 00 2 9595 1 932 100 212 00 0 8329 0 753 11 51 80 15 0746 3 812 56 132 80 2 8665 1 894 12 53 60 14 4462 3 773 57 134 60 2 7769 1 857 13 55 40 13 8482 3 733 58 136 40 2 6906 1 820 14 57 20 13 2787 3 693 59 138 20 2 6076 1 784 15 59 00 12 7365 3 652 60 140 00 2 5275 1 749 16 60 80 12 2199 3 611 61 141 80 2 4504 1 713 9 9 17 62 60 11 7275 3 569 62 143 60 2 3760 1 679 18 64 40 11 2582 3 527 63 145 40 2 3044 1 645 19 66 20 10 8107 3 485 64 147 20 2 2353 1 612
12. 8 2 4 KO DC90 120V GY3 BK6 Solenoid Valve 2 Okay 0 8 2 4 KO DC90 120V R5 BK6 Solenoid Valve 3 Okay 0 8 2 4 KO DC90 120V BL4 BK6 Solenoid Valve 4 Okay 0 8 2 4 KO 95 96 96 Page SVC 820 Tankless Gas Troubleshooting Manual Does the water volume control motor have W2 BK8 DC8 16V proper voltage Does the water volume control motor have R7 BK8 DC8 16V proper voltage C Less than 1V DC ee ads Limiter on Is the water volume control position switch DC4 6 V Limiter OKs Off Does the water by pass control motor have W2 BK8 DC8 16V proper voltage Does the water by pass control motor have R7 BK8 DC8 16V proper voltage B Less than 1V DC Limiter on Is the water by pass control position switch G6 BK8 DC4 6 V Limiter Off OK SVC 820 Tankless Gas Troubleshooting Manual Page 97 Inlet Outlet amp Heat Exchanger Thermistor All Models CG CF kQ V C PF kQ V CUBES kQ V 25 13 00 87 7437 4 746 20 68 00 10 3839 3 442 65 149 00 2 1687 1 579 24 11 20 82 9816 4 732 21 69 80 9 9767 3 399 66 150 80
13. Board Is Flame Rod s i detecting flame NO YE Attempt to operate unit again IF the unit malfunctions due to an Error Code 12 Flame Rods s are OK CHECK GAS VENTING amp GROUND Remove and clean Flame Rod s Attempt to operate unit again IF Flame Rod s still does not detect flame Replace Flame Rod s 45 46 46 Page NOTES SVC 820 Tankless Gas Troubleshooting Manual I l l l l l l l l l l l l l SVC 820 Tankless Gas Troubleshooting Manual Page 47 13 Error Code Explanation Indoor units ONLY Flame Rod 2 FL 2 is detecting poor combustion This is commonly caused by inadequate or improperly installed VENTING venting includes fresh air intake and exhaust Other possible causes Poor or NO ground connection dirty or defective FL 2 If unit shuts down 5 times within a 4 hour period due to an error code 13 the unit must be reset by performing reset procedure on page 21 First Check VENTING Primary cause is blockage of the Fresh Air Intake Vent Diagnostic Checks e VENTING amp GAS SUPPLY always check gas supply at MAX BTU s REFER TO USE amp CARE MANUAL Ground Connection Flame Rod FL 2 VENTING Visually inspect venting for possible blockage and or recirculation of exhaust Approved Venting Materials Approved Vent Terminations Vent Lengths Location Of Vent Termination Recirculation of exhaust Blocked Ventin
14. Error Code 90 Error Code SVC 820 Tankless Gas Troubleshooting Manual TABLE OF CONTENTS Diagnostic Charts Diagnostic POolnts cessed este Teese eti aeter e Ure eso nhetece e Ted edid eade adings for THEKIMIStOlS a rette eee te eee eid i e s 97 Resistance Re 64 66 68 70 72 74 76 78 80 82 84 86 88 90 91 92 92 93 Page 3 4 Page SVC 820 Tankless Gas Troubleshooting Manual Specifications common to all models Model See specification sheets for current models and specs Purpose Domestic Hot Water DHW supply for showers cleaning and laundry Rated Gas Input Btu Hr See specification sheets for current models and specs Dimensions See specification sheets for current models and specs Indoor Wall Mounting Can be vented horizontally or vertically Outdoor Wall Mounting Venting not required Installation Mid Efficiency ONLY uses Stainless steel Category Ill 316L Certified concentric venting for indoor installation High Efficiency Uses PVC CPVC ABS or Stainless Steel Category III 316L Certified venting for indoor installation Working Water Pressure 14 PSI minimum 150 PSI maximum Minimum Water Flow 0 4 GPM to activate burner can be reduced to 26 GPM once burner is activated Maximum Water Flow Based on 35 degree rise See specification sheets for current models and specs Gas Connection 3 4 NPT Male Water Connection 3 4 NPT Male Vent Size
15. NO Replace Control Board 108 132 Volts AC YES Remove Igniter Coil cable from Igniter Rod While unit is attempting to ignite hold end of Igniter Coil cable 1 8 from end of Igniter Rod Make sure you hold Igniter Coil cable on the rubber insulation while performing this check Replace Igniter Coil Does spark arc across Igniter Coil NO cable and Igniter Rod YES Remove Igniter Rod and clean Reconnect Igniter Coil cable and Igniter Rod Attempt to operate unit again Igniter Rod is OK Replace Igniter Rod IF unit fails again due to Error Code 11 Is spark visible through sight glass IF flame IS visible diagnose Flame Rods YES NO IF flame is NOT visible diagnose Gas Control Valve 35 36 36 Page SVC 820 Tankless Gas Troubleshooting Manual FLAME ROD S DIAGNOSTICS flame IS visible Flame Rod s Remove and reinsert terminals on Flame Rods s Attempt to operate unit again IF 11 Error Code does NOT Turn power OFF Remove and reinsert white connector display unit had a loose connection M and blue connector T on Control Board Indoor Models ONLY 2 Flame Rods Sight Glass Locate sight glass While unit is attempting to ignite determine if flame is touching Flame Rod s IF NO On Remote Control go to Maintenance Mode OY table For Maintenance Mode instructions go to page 16 remove any fore
16. Rating Gas Regulator Gas Shut Off Valves Air In Gas Line Soy Ver Visually inspect venting for possible blockage and or recirculation of exhaust 1 Approved Venting Materials 26 en Ha ee ee 2 Approved Vent Terminations 3 Vent Lengths 4 Location Of Vent Termination Recirculation of exhaust 5 Blocked Venting 6 Venting Not Sealed Properly N N id a SVC 820 Tankless Gas Troubleshooting Manual Page 27 DIP 42 SETTING Locate the two DIP switches at top right of PCB Switch labeled DIP 2 is the bottom switch DO NOT ALTER ANY OTHER SWITCHES Dip switch adjustment 3 280 feat 1 000 m thru feat m 6 560 2 000 If altitude is above 3 280 ft 1 000 m and below 6 560 ft 2 000 m change the third switch on DIP 2 to the ON position UP Sea Level to 3 280 Feet The factory settings for this switch should all b in tha OFF position DOWN Dip switch i adjustment 6 560 feat 2 000 m thru 9 840 feet 3 000 m If altitude is above 6 560 ft 2 000 m and below 9 840 ft 3 000 m change the fourth switch to the ON position UP 28 28 Page NOTES SVC 820 Tankless Gas Troubleshooting Manual
17. Rod s 83 84 84 Page SVC 820 Tankless Gas Troubleshooting Manual 76 Error Code Explanation Communication Fault with Remote Control Diagnostic Checks Remote Control is not communicating with Control Board e Remote Control e Wiring REMOTE THERMOSTAT DIAGNOSTICS Turn power OFF Remove and reconnect Remote Control wiring terminals at bottom of unit Attempt to operate unit again IF 76 Error Code does NOT display unit had a loose connection Visually inspect Remote Control wiring for damaged or loose terminals IF 76 Error Code IS displayed continue to diagnostic chart on next page SVC 820 Tankless Gas Troubleshooting Manual Page 85 76 Error Code Diagnostic Chart Attempt to operate unit again If the unit Unplug unit and remove Remote Did the unit go to malfunctions due to an Error Code 76 main burner Thermostat wires from wiring terminals o NO on bottom of unit Plug unit in and open Replace Remote Control a hot water source YES Unplug unit Use a short piece of new thermostat wire to connect the Remote Control directly to Remote Control wiring terminals at bottom of unit Plug unit in and open a hot water source Replace Remote Control Did the unit go to i main burner NO YE The wiring is defective Replace Remote Control wiring 85 86 Page SVC 820 Tankless Gas Troubleshooting Manual 79 Error Code Explanation Blower Mot
18. V TR r ee ee dad Kg E LLL du med ems mm LA cu Gu LE uem c uL LE LS ILL Eel l Ll Im 43 44 44 Page SVC 820 Tankless Gas Troubleshooting Manual FLAME ROD S DIAGNOSTICS flame IS visible Flame Rod s Remove and reinsert terminals on Flame Rod s Attempt to operate unit again IF 12 Error Code does NOT Turn power OFF Remove and reinsert white connector display unit had a loose connection M and blue connector T on Control Board Indoor Models ONLY 2 Flame Rods Sight Glass Locate sight glass While unit is attempting to ignite On Remote Control go to Maintenance Mode OY table determine if flame is touching Flame Rod s IF NO For Maintenance Mode instructions go to page 16 remove any foreign debris IF foreign debris NOT present CHECK GAS SUPPLY amp VENTING Continue to diagnostic chart on next page SVC 820 Tankless Gas Troubleshooting Manual Page 45 FLAME ROD s Diagnostic Chart Cycle unit ON and check AC Volts at white M amp blue T connectors Is the AC voltage OK NO 1 100 AC VOLTS YES Cycle unit ON while in Maintenance Mode check Flame Rod s status under table OY IF detecting flame Maintenance Mode will display Indoor Models 05 Outdoor Models 01 Attempt to operate unit again IF the unit malfunctions due to an Error Code 12 Replace Control
19. Warning Code Explanation The Control Board has detected possible lime build up inside the heat exchanger To prevent permanent damage to the unit the unit must be drained and flushed Flushing procedures may need to be repeated for excessive lime and scale build up To reset 1L Code hold down the MIN and MAX buttons at the same time for 10 seconds Lime and scale flushing procedure for tankless water heaters In areas with hard water conditions the tankless water heater can develop lime and scale deposits in the heat exchanger These deposits can restrict the water flow and degrade the performance of your water heater These instructions are to provide a safe and effective means to remove lime and scale build up in the heat exchanger of your tankless water heater If you are not comfortable with this procedure then seek the assistance of a plumbing professional Flushing Procedure with Isolation Valves If your tankless water heater is not installed with isolation valves it is recommended that you seek the assistance of a plumbing professional 10 11 12 Turn off the electricity and gas to the tankless water heater Do not perform this procedure with power or gas turned on damage to the water heater can occur Shut off the main water supply valve to the tankless water heater Consult the instructions provided by the isolation valve manufacturer for specifics in using their valve assemblies Attach a
20. With the water flowing measure 2 5 DC volts between the Brown and Black wire This is measuring water flow thru the control IF you have a reading and no main burner replace the PCB If you do not have a reading replace the water flow sensor SVC 820 Tankless Gas Troubleshooting Manual Page 23 P1 Warning Code Explanation No hot water is delivered when water is flowing through unit and Remote Control displays P1 When water flow does not reach a minimum 0 4 GPM rate 35 A T for five seconds P1 warning code is displayed Possible Causes e Not Enough Water Flow Water Flow Turn the water supply to the unit off Turn the remote thermostat off wait 10 seconds and turn the remote thermostat on Turn the water supply to the unit on and check the nearest hot water fixture for hot water If you have hot water then the unit needed to be reset Your water lines might be crossed Make sure your hot and cold water supply lines are connected to the appropriate hot and cold water connections on the unit Water flow might be too low Open multiple hot water fixtures If unit fires then there is not enough water flow to engage the unit at a particular fixture Check your fixture aerator screen s for debris Clean if necessary Your water flow may be restricted by a dirty In Line Water Filter Remove the water filter and inspect Clean if necessary 23 24 24 Page SVC 820 Tankless Gas Troubleshooting Manual IL
21. bj A 4 Is there a visible Does OY Status in Water heater appears bj flame while unit a Maintenance Mode NC gip to be normal is OFF N indicate presence 7 Attempt to operate unit AC of flame after 5 lt s lt again s seconds pd SX S L 4 s ve N P4 YES YES Visibly inspect burner chamber through Disconnect Molex Connector from Flame Sight Glass Rods s Cycle the water heater 3 times by turning unit on off on off on off 2T N s P N P4 Nd 4 Is debris visible Does OY Status in Sy Clean or Replace Flame on burner FA Maintenance Mode Rod s 4 assembly Bg e indicate presence NY of flame after 5 MS seconds Pid SS v 4 N 4 s Pid gt 7 YES YES Remove and clean burner assembly Attempt to operate unit again If the unit malfunctions due to an Error Code 51 Replace Control Board Attempt to operate unit again If the unit displays 51 Error Code and flame IS visible while unit is OFF Replace Gas Control Valve 71 72 Page SVC 820 Tankless Gas Troubleshooting Manual 52 Error Code Explanation PGFR Proportional Gas Flow Regulator Diagnostic Checks malfunction The PGFR is the only modulating valve in the e PGFR Gas Control Valve PGFR DIAGNOSTICS Locate PGFR valve on lower right of unit Remove and Turn power OFF Remove and reinsert connector R reinsert Molex connector with red wire and Molex on Control Board
22. small garden hose on each drain valve Connect the cold water hose to the output of a small circulation pump A pond pump or similar model can be used for this application Pour approximately five gallons of virgin food grade white vinegar into a pail Place the inlet hose of the pump and the drain hose from the hot water heater into the pail Open the drain valves and turn on the pump Allow solution to circulate for approximately 45 minutes to an hour Turn off the pump and drain the vinegar from water heater Close the cold water drain valve Open the main cold water supply valve and allow fresh water to flush through the water heater for at least 5 minutes to remove all traces of vinegar from the system Close the cold water main valve and remove water filter screen located in cold water inlet of water heater Clean the screen of any sediment or dirt and reinstall the filter See the Use and Care Manual provided with your tankless water heater for detailed instructions Turn on the water shutoff valves run a hot water tap to purge any air from the water lines and check the system for any leaks Turn on gas electricity and remote control thermostat and set the desired temperature Run hot water from several locations to check the operation and performance of the water heater SVC 820 Tankless Gas Troubleshooting Manual Page 25 03 Error Code Only for manifold installations utilizing EZ Link MIC 6 or MIC 185 Explana
23. to operate properly T Gas Type LP or Natural Gas Gas Pressure Gas Pipe Size Gas Flex Line Not To Exceed 36 In Length has the proper ID Inside Diameter and correct BTU rating Gas Regulator Gas Shut Off Valves Air In Gas Line Visually inspect venting for possible blockage and or recirculation of exhaust 1 Approved Venting Materials Approved Vent Terminations Vent Lengths Location Of Vent Termination Recirculation of exhaust Blocked Venting Venting Not Sealed Properly a LLLI Tiet TE E LLLI IIl ww 33 34 34 Page SVC 820 Tankless Gas Troubl eshooting Manual IGNITER ROD DIAGNOSTICS spark is NOT visible Igniter Coil Turn power OFF Remove and reinsert connector H on Control Board Igniter Rod Remove and reinsert Igniter Coil cable on Igniter Rod Turn power ON Remove and reinsert white Molex connector at Igniter Coil mounted on right side of unit Sight Glass While unit is attempting to ignite determine IF spark is visible through sight glass IF YES unit had a loose connection IF NO continue to diagnostic chart on next page SVC 820 Tankless Gas Troubleshooting Manual Page 35 IGNITER ROD Diagnostic Chart Attempt to operate unit again Check AC Volts across 2 grey wires on IF Igniter Rod does not spark and unit Is the voltage malfunctions due to Error Code 11 OK connector H while unit is attempting to ignite
24. 13 2787 3 693 59 138 20 2 6076 1 784 15 59 00 12 7365 3 652 60 140 00 2 5275 1 749 16 60 80 12 2199 3 611 61 141 80 2 4504 1 713 9 7 17 62 60 11 7275 3 569 62 143 60 2 3760 1 679 18 64 40 11 2582 3 527 63 145 40 2 3044 1 645 19 66 20 10 8107 3 485 64 147 20 2 2353 1 612 98 98 Page SVC 820 Tankless Gas Troubleshooting Manual Ambient Thermistor RTG64X RTG84X RTG95X RTGH95X RTGH95DV RESISTANCE CHART C CP kQ V CC F kQ v C CF ko V 25 13 00 72 1585 4 694 20 68 00 6 2677 2 857 65 149 00 1 0432 0 908 24 11 20 67 6926 4 675 21 69 80 5 9870 2 801 66 150 80 1 0079 0 883 23 9 40 63 5355 4 656 22 71 60 5 7207 2 745 67 152 60 0 9739 0 858 22 7 60 59 6638 4 635 23 73 40 5 4680 2 689 68 154 40 0 9413 0 834 21 5 80 56 0560 4 613 24 75 20 5 2280 2 633 69 156 20 0 9100 0 811 20 4 00 52 6923 4 591 25 77 00 5 0000 2 577 70 158 00 0 8799 0 788 19 2 20 49 5546 4 567 26 78 80 4 7834 2 522 71 159 80 0 8510 0 767 18 0 40 46 6262
25. 2 1044 1 546 23 9 40 78 5129 4 718 22 71 60 9 5880 3 355 67 152 60 2 0424 1 515 22 7 60 74 3177 4 703 23 73 40 9 2169 3 311 68 154 40 1 9826 1 483 21 5 80 70 3773 4 687 24 75 20 8 8626 3 267 69 156 20 1 9248 1 453 20 4 00 66 6745 4 671 25 77 00 8 5241 3 223 70 158 00 1 8691 1 423 19 2 20 63 1933 4 654 26 78 80 8 2007 3 178 71 159 80 1 8153 1 393 18 0 40 59 9192 4 636 27 80 60 7 8915 3 134 72 161 60 1 7633 1 364 17 1 40 56 8382 4 618 28 82 40 7 5960 3 089 73 163 40 1 7131 1 336 16 3 20 53 9378 4 599 29 84 20 7 3134 3 044 74 165 20 1 6646 1 308 15 5 00 51 2062 4 580 30 86 00 7 0431 2 999 75 167 00 1 6178 1 280 14 6 80 48 6325 4 559 31 87 80 6 7844 2 954 76 168 80 1 5725 1 253 13 8 60 46 2064 4 538 32 89 60 6 5368 2 909 77 170 60 1 5288 1 227 12 10 40 43 9185 4 517 33 91 40 6 2998 2 864 78 172 40 1 4865 1 201 11 12 20 41 7602 4 494 34 93 20 6 0729 2 819 79 174 20 1 4456 1 176 10 14 00 39 7230 4 471 35 95 00 5 8555 2 774 80 176 00 1 4060 1 151 9 15 80 37 7996 4 447 36 96 80 5 6473 2 729 81 177 80 1 3678 1 127 8 17 60 35 9828 4 422 37 98 60 5 4477 2 684 82 179 60 1 3308 1 103 7 19 40 34 2660 4 397 38 100 40 5 2564 2 640 83 181 40 1 2949 1 080 6 21 20 32 6430 4 371 39 102 20 5 0729 2 595 84 183 20 1 2603 1 057 5 23
26. 464 0 32 00 16 8103 3 908 45 113 00 2 1741 1 581 90 194 00 0 4668 0 452 1 33 80 15 9466 3 862 46 114 80 2 0911 1 540 91 195 80 0 4531 0 440 2 35 60 15 1330 3 815 47 116 60 2 0118 1 499 92 197 60 0 4398 0 428 3 37 40 14 3664 3 767 48 118 40 1 9360 1 459 93 199 40 0 4270 0 416 4 39 20 13 6438 3 719 49 120 20 1 8635 1 420 94 201 20 0 4146 0 405 5 41 00 12 9623 3 669 50 122 00 1 7941 1 381 95 203 00 0 4027 0 395 6 42 80 12 3194 3 619 51 123 80 1 7277 1 344 96 204 80 0 3911 0 384 7 44 60 11 7126 3 568 52 125 60 1 6641 1 307 97 206 60 0 3800 0 374 8 46 40 11 1397 3 516 53 127 40 1 6033 1 272 98 208 40 0 3692 0 364 9 48 20 10 5986 3 464 54 129 20 1 5450 1 237 99 210 20 0 3588 0 355 10 50 00 10 0873 3 411 55 131 00 1 4892 1 203 100 212 00 0 3488 0 345 11 51 80 9 6040 3 357 56 132 80 1 4357 1 170 12 53 60 9 1470 3 303 57 134 60 1 3845 1 138 13 55 40 8 7148 3 248 58 136 40 1 3354 1 106 14 57 20 8 3058 3 193 59 138 20 1 2883 1 076 15 59 00 7 9186 3 138 60 140 00 1 2431 1 046 16 60 80 7 5519 3 082 61 141 80 1 1997 1 017 17 62 60 7 2046 3 026 62 143 60 1 1582 0 989 18 64 40 6 8755 2 970 63 145 40 1 1183 0 961 19 66 20 6 5635 2 914 64 147 20 1 0800 0 934
27. 6 Is the resistance OK and grey wire 3 on connector K Replace Gas Control Valve 0 8k 2 4k Ohms Measure resistance across black wire 6 Is the resistance OK and red wire 5 on connector K Replace Gas Control Valve 0 8k 2 4k Ohms Measure resistance across black wire 6 Is the resistance OK and blue wire 4 on connector K Replace Gas Control Valve 0 8k 2 4k Ohms Gas Control Valve is OK Continue to next page SVC 820 Tankless Gas Troubleshooting Manual Page 41 CONTROL BOARD Diagnostic Chart All voltage checks must be performed while unit is attempting to go to main burner and Molex connector K IS connected to Control Board Restart unit after each voltage check Replace Control Board Measure DC voltage across black wire 6 Is the voltage and yellow wire 1 on connector K OK 90 120 DC Volts Measure DC voltage across black wire 6 Is the voltage and white wire 2 on connector K OK Replace Control Board 90 120 DC Volts Measure DC voltage across black wire 6 Is the voltage OK and grey wire 3 on connector K Replace Control Board 90 120 DC Volts Measure DC voltage across black wire 6 and red wire 5 on connector K Is the voltage OK Replace Control Board 90 120 DC Volts Measure DC voltage across black wire 6
28. 7 12 10 40 43 9185 4 517 33 91 40 6 2998 2 864 78 172 40 1 4865 1 201 11 12 20 41 7602 4 494 34 93 20 6 0729 2 819 79 174 20 1 4456 1 176 10 14 00 39 7230 4 471 35 95 00 5 8555 2 774 80 176 00 1 4060 1 151 9 15 80 37 7996 4 447 36 96 80 5 6473 2 729 81 177 80 1 3678 1 127 8 17 60 35 9828 4 422 37 98 60 5 4477 2 684 82 179 60 1 3308 1 103 7 19 40 34 2660 4 397 38 100 40 5 2564 2 640 83 181 40 1 2949 1 080 6 21 20 32 6430 4 371 39 102 20 5 0729 2 595 84 183 20 1 2603 1 057 5 23 00 31 1082 4 344 40 104 00 4 8970 2 551 85 185 00 1 2268 1 035 4 24 80 29 6561 4 316 41 105 80 4 7282 2 507 86 186 80 1 1943 1 013 3 26 60 28 2819 4 287 42 107 60 4 5663 2 464 87 188 60 1 1629 0 992 2 28 40 26 9807 4 258 43 109 40 4 4109 2 421 88 190 40 1 1324 0 971 1 30 20 25 7484 4 228 44 111 20 4 2617 2 378 89 192 20 1 1029 0 950 0 32 00 24 5807 4 197 45 113 00 4 1185 2 335 90 194 00 1 0744 0 930 1 33 80 23 4739 4 166 46 114 80 3 9809 2 293 91 195 80 1 0467 0 911 2 35 60 22 4245 4 134 47 116 60 3 8487 2 251 92 197 60 1 0199 0 892 3 37 40 21 4291 4 101 48 118 40 3 7217 2 210 93 199 40 0 9939 0 873 4 39 20 20 4846 4 067 49 120 20 3 5996 2 169 94 201 20 0 9687 0 854 5 41 00 19 5880 4 032 50 122 00 3 4823 2 128 95 203 00 0 9443 0 837 6 42 80 18 7367 3 997 51
29. 9 80 Error Code Diagnostic Chart On Remote Control go to Maintenance Mode OY table For Maintenance Mode instructions go to page16 While viewing burner chamber through All Maintenance Mode OY readings should be done immediately after In 10 second intervals cycle the water will display heater 3 times by turning unit on off on off on off sight glass turning the unit OFF IF Flame Rod s is detecting flame Maintenance Mode i Indoor Units 05 X Outdoor Units 01 N 7 h A a aa ee Fak pS Pe Ly A pk ee Eee eee eh ee NP HOT eee en A1 d S N s A 4 Is there a visible Does OY Status in y Water heater appears bj x Maintenance Mode N to be normal 4 indicat NO N indicate presence P Attempt to operate iN A of flame after 5 p flame while unit is OFF again X seconds ka Visibly inspect burner chamber through Disconnect Molex Connector from Flame sight glass Rod s Cycle heater 3 times by turning unit on off on off on off P N Is debris visible f Does OY Status in s Clean or Replace Flame on burner FA Maintenance Mode Rod s assembly indicate presence NY of flame after 5 Ts seconds Pid Remove and clean burner assembly Attempt to operate unit again If unit displays 80 Error Code Replace Control Board Attempt to operate again If unit displays 80 Error Cod
30. C 820 Tankless Gas Troubleshooting Manual Page 49 FLAME ROD s Diagnostic Chart Cycle unit ON and check AC Volts at white M amp blue T connectors Is the AC voltage OK NO 1 100 AC VOLTS YES Cycle unit ON while in Maintenance Mode check Flame Rod s status under table OY IF detecting flame Maintenance Mode will display Indoor Models 05 Outdoor Models 01 Attempt to operate unit again IF the unit malfunctions due to an Error Code 13 Replace Control Board Is Flame Rod s i detecting flame NO YE Attempt to operate unit again If the unit malfunctions due to an Error Code 13 Flame Rod s are OK Unit operation is normal CHECK VENTING Remove and clean Flame Rod s Attempt to operate unit again IF Flame Rods still does not detect flame Replace Flame Rod s 49 50 Page SVC 820 Tankless Gas Troubleshooting Manual 14 Error Code Explanation Diagnostic Checks Mid amp High Efficiency Over Heat Limiter OHL e Mid amp High Efficiency malfunction OHL High Efficiency ONLY e High Efficiency ONLY Over heat condition in the venting has triggered the Over Over Temp Limit Switch Temp Limit Switch OHL DIAGNOSTICS Mid Efficiency ONLY Turn power OFF Remove and reinsert white IF 14 Error Code does NOT display unit had a loose connector U on Control Board white Molex with 2 connection IF 14 Error Code IS display
31. Code Explanation Ambient Thermistor malfunction SVC 820 Tankless Gas Troubleshooting Manual Diagnostic Checks e Ambient Thermistor AMBIENT THERMISTOR DIAGNOSTICS Turn power OFF Remove connector R on Control Board Measure resistance between Black 3 amp Blue 7 wires Refer to Data Table for resistance value IF OK attempt to operate unit again IF 34 Error Code does NOT display unit had a loose connection Molex Connectors o jog J Te Na Bottom of Unit Turn power OFF Remove 3 screws for Control Board mounting bracket Remove connectors M T amp G Pull Control Board out of way to access BLUE Molex for Ambient Thermistor located near the Blower Motor Separate top and bottom of BLUE Molex for Ambient Thermistor Top of Molex has 2 black wires and 1 blue wire Bottom of Molex has 2 black wires Continue to Diagnostic Chart on next page Ambient Thermistor Data Table 64DV 84DV 95DV 7K 23K Ohms 64X 84X 95X 2K 72K Ohms H95DV H95X 2K 72K Ohms 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 U U 1 1 1 1 1 U Screws Page 67 SVC 820 Tankless Gas Troubleshooting Manual 34 Error Code Diagnostic Chart Clean Ambient Thermistor Retest Thermistor IF tests OK the water heater appears to be normal Attempt to operate NO unit again IF resistance NOT OK Is the resistance to the Ambient Thermistor OK Check t
32. Error Code for diagnostics IF sensors test OK continue to next page eemsuusanaT c c E23 Q i Black 3 amp Blue 7 Wires Ambient Thermistor 1 64DV 84DV 95DV 7K 23K Ohms 64X 84X 95X 2K 72K Ohms i H95DV H95X 2K 72K Ohms Black 3 amp White 6 Wires Inlet Thermistor 7K 23K Ohms Error Code 31 Black 3 amp Yellow 5 Wires Heat Exchanger Thermistor 7K 23K Ohms Error Code 32 Black 3 amp Red 4 Wires Outlet Thermistor 7K 23K Ohms Error Code 33 Black 3 amp Blue 7 Wires Ambient Thermistor Refer to Data Table Error Code 34 ma SVC 820 Tankless Gas Troubleshooting Manual Page 69 35 Error Code Diagnostic Chart Go to appropriate Sensor Error Code to Check resistance for all Thermistors at diagnose Is the resistance un Molex Connector R for all Th rerz NO Inlet Error Code 31 ermistors OK Heat Exchanger Error Code 32 Outlet Error Code 33 Ambient Error Code 34 YES Attempt to operate the unit again The water heater appears to be operating normally Ambient Thermistor Data Table Did the unit lockout on Error Code 35 64DV 84DV 95DV 7K 23K Ohms NO 64X 84X 95X 2K 72K Ohms M a RIGEN TUUM E eT H95DV H95X 2K 72K Ohms YES Replace Control Board 69 70 Page SVC 820 Tankless Gas Troubleshooting Manual 51 Error Code Explanation Gas Co
33. HL Check heat exchanger for cracks and or separations Inspect Overheat Wrap Overheat wrap failure Replace unit Uto iN cS Check thermal overload sensor condensing models only 15 Maintenance Boiling Safety Device Heat Exchanger temperature reached 207 F degrees for more than 15 seconds Flush Heat Exchanger lime scale buildup 2 Check for closed water heater inlet valve or restrictions in cold water inlet pipe must be fully open 3 Oncommercial water heater lower set point temperature below 180 F at high altitudes If maintenance requirements are met 1 Check Heat Exchanger Thermistor 16 Maintenance Outlet Water Temperature Is Above Remote Thermostat Setting 1 Check for clogged Heat Exchanger 2 Check for restrictions in airflow around unit and vent terminal If maintenance requirements are met 1 Check Outlet Thermistor 2 Check Heat Exchanger Thermistor 3 Check gas valve 11 12 12 Page SVC 820 Tankless Gas Troubleshooting Manual 1 Turn off water Disconnect Remote Control and retry Malfunction Of e 24 l 2 Verify unit is electrically grounded Operational Switch 3 Press MIN and MAX button on Control Board to reset Condensing Only 1 Ensure shipping cap for drain line is removed and drain line is not blocked Condensing Only 2 Clear all neutralizer drainage ports inside of unit 3 Clear neutralizer drainage line outside of
34. Is the voltage and blue wire 4 on connector K OK Replace PCB 90 120 DC Volts Control Board is OK IF all components tested OK CHECK GAS VENTING amp GROUND 41 42 42 Page NOTES SVC 820 Tankless Gas Troubleshooting Manual SVC 820 Tankless Gas Troubleshooting Manual 12 Error Code Explanation Commonly a result of inadequate GAS SUPPLY Unit detected the presence of flame then Flame Diagnostic Checks Rod lost flame recognition e GAS SUPPLY amp VENTING e Flame Rods First Check GAS SUPPLY amp VENTING Page 43 P 7 E GAS SUPPLY amp VENTING I REFER TO USE amp CARE MANUAL l i Make sure you have sufficient fuel for the unit to operate properly l 1 Gas Type LP or Natural Gas l 2 Gas Pressure 3 Gas Pipe Size l 4 Gas Flex Line Not To Exceed 36 In Length has the proper ID Inside Diameter and correct BTU rating 5 Gas Regulator 6 Gas Shut Off Valves I 7 Air In Gas Line I Visually inspect venting for possible blockage and or recirculation of exhaust 1 Approved Venting Materials 2 Approved Vent Terminations 3 Vent Lengths 4 Location Of Vent Termination Recirculation of exhaust 5 Blocked Venting I 6 Venting Not Sealed Properly N N
35. Mid Efficiency 3 5 Concentric Vent High Efficiency 2 or 3 Two Pipe Venting optional concentric vent termination Max Vent Length See Use amp Care Manual for each product type Inlet Gas Pressure Natural Gas Minimum 4 0 w c Maximum 10 5 w c L P Gas Minimum 8 0 w c Maximum 14 0 w c Hot Water Supply Factory Setting 85F 140F Up to 140 with Override Adjustment Temperatures Commercial Setting Up to 185F via program chip Rating 120 VAC 60Hz 3 Amps Electrical Wire Indoor Models 3 Prong Edison Power Supply Cord Outdoor Models require field wiring Fuse 3A Fuse x 2 line voltage Safety Devices Flame Rods Overheat Film Wrap for Heat Exchanger Heat Exchanger Thermistor Boiling Point Safety Electronic Burner and Combustion Monitoring and Control Freeze Protection Minus 30F Without Wind Chill Factor with power applied Remote Control Standard Main Remote Control UMC 117 included Optional Bath Remote Control USC1 117 120 F Max Limit Optional Second Bath Remote USC2 117 120 F Max Limit Only one of each type remote above can be installed on a single unit Only one of each type remote above can be installed on multiple manifold units SVC 820 Tankless Gas Troubleshooting Manual Sequence of Operations Page 5 ACTION EXPLANATION Hot water faucet is open creating a demand Hot water draw initiates water flow thru the water heater
36. S Attempt to operate unit again Is the DC voltage OK If the unit malfunctions due to an Error NO Code 65 Replace Control Board YE Turn power to unit OFF then ON again and turn water flow on Check DC Voltage across Green amp Black Wires at connector C 4 6 DC VOLTS Attempt to operate unit again Attempt to operate unit again Is the DC voltage OK If the unit malfunctions due to an Error NO Code 65 If the unit malfunctions due to an Error Code 65 YES Replace Water Control Valve Replace Control Board 77 78 Page SVC 820 Tankless Gas Troubleshooting Manual 66 Error Code Explanation Water Bypass Valve malfunction Hot outlet Diagnostic Checks water temperature is above or below set point on Remote e Water Bypass Valve Control WATER BYPASS VALVE DIAGNOSTICS wal i Ir V Y EE f 273 Bottom of Unit Turn power OFF Remove and reinsert connector B on Control Board Attempt to operate unit again IF Turn power OFF Remove 3 screws for Control Board 66 Error Code does NOT display unit had a loose connection G Pull Control Board out of way to access Water Bypass Valve mounting bracket Remove connectors M T amp Water Bypass Valve Visually inspect Water Bypass Valve wiring harness for loose or damaged terminals It is located right of the Blower Motor below two copper Top of Unit Bottom of Unit pipes Reassemble unit and con
37. connector with black wire on PGFR Attempt to operate unit again IF 52 Error Code does NOT display unit had a loose connection IF 52 Error Code IS displayed continue to diagnostic chart on next page Control Board SVC 820 Tankless Gas Troubleshooting Manual Page 73 52 Error Code Diagnostic Chart Attempt to operate unit again While unit is attempting to go to main Is the DC voltage OK If the unit malfunctions due to an Error NO Code 52 burner check DC voltage across red wire 1 and black wire 2 on Connector R 1 5 14 DC VOLTS Replace Control Board YES While unit is attempting to go to main burner check DC voltage across red and black wires at PGFR 1 5 14 DC VOLTS Replace wiring harness for Connector R on Control Board Is the DC voltage xs NO YE Attempt to operate unit again If the unit malfunctions due to an Error Code 52 Replace Gas Control Valve 73 74 74 Page SVC 820 Tankless Gas Troubleshooting Manual 61 Error Code Explanation Blower Motor malfunction Blower Motor speed was not appropriate to allow proper combustion Diagnostic Checks e Blower Motor BLOWER MOTOR DIAGNOSTICS Turn power OFF Remove and reinsert connector G on Control Board Attempt to operate unit again IF 61 Error Code does NOT display unit had a loose connection Remove 3 screws holding Blower Motor in place Clean Blow
38. ctors 64 Bottom of Unit Turn power OFF Remove 3 screws for Control Board mounting bracket Remove connectors M T amp G Pull Control Board out of way to access BLACK Molex for Outlet Thermistor located near the Blower Motor Separate top and bottom of BLACK Molex for Outlet Thermistor Top of Molex has 2 black wires and 1 red wire Bottom of Molex has 2 black wires Continue to Diagnostic Chart on next page Outlet Thermistor SVC 820 Tankless Gas Troubleshooting Manual Page 65 33 Error Code Diagnostic Chart Clean Scale Build Up on Outlet Thermistor Retest Thermistor IF tests OK the water heater appears to be normal Attempt to Check the resistance across 2 black wires Is the resistance to the Outlet Thermistor OK on bottom Molex NO operate unit again IF resistance NOT OK 7k 23K Ohms Replace Outlet Thermistor YES Remove Molex from Connector R at Control Board Check continuity from black 83 wire at Connector R Molex and black wires at black Molex located behind Control Board Check continuity from red 4 wire at Connector R Molex and red wire at Black Molex located behind Control Board Replace wiring harness for Connector R on Control Board Is the continuity across all wires OK NO YES Attempt to operate unit again If the unit malfunctions due to an Error Code 33 Replace Control Board 65 66 66 Page 34 Error
39. d Replace wiring harness for Connector R on Control Board Is the continuity across all wires OK NO YES Attempt to operate unit again If the unit malfunctions due to an Error Code 31 Replace Control Board 61 62 Page SVC 820 Tankless Gas Troubleshooting Manual 32 Error Code Explanation Diagnostic Checks Heat Exchanger Thermistor malfunction e Heat Exchanger Thermistor HEAT EXHCANGER THERMISTOR DIAGNOSTICS Screws Bottom of Unit Turn power OFF Remove connector R on Control Board Measure resistance between Black 3 amp Turn power OFF Remove 3 screws for Control Board YELLOW 5 wires 7K 23K Ohms IF OK attempt to operate unit again IF 32 Error Code does NOT display mounting bracket Remove connectors M T amp G Pull Control Board out of way to access YELLOW unit had a loose connection Molex for Heat Exchanger Thermistor located near the Rig cuc RN M NEM ER Blower Motor High Efficiency Condensing Units ONLY GREEN wire amp GREEN Molex 7 Si luris otim plici M High Efficiency Condensing Units ONLY Molex Connectors GREEN wire amp GREEN Molex Separate top and bottom of YELLOW Molex for Heat Exchanger Thermistor Top of Molex has 2 black wires and 1 YELLOW wire Bottom of Molex has 2 white wires Continue to Diagnostic Chart on next page
40. displayed continue to diagnostic chart on next page SVC 820 Tankless Gas Troubleshooting Manual Page 57 24 Error Code Diagnostic Chart Unplug unit and remove Remote Control The wiring is defective wires from wiring terminals on bottom of Did the unit display Error Code 24 unit Use a new short piece of wire to Replace Remote Control wiring connect the Remote Control directly to the Remote Control Wiring Terminals located at bottom of unit Plug unit in and open a hot water source Replace Remote Control 57 58 58 Page NOTES SVC 820 Tankless Gas Troubleshooting Manual SVC 820 Tankless Gas Troubleshooting Manual Page 59 29 Error Code Explanation High Efficiency Condensing Units ONLY Condensate Drain is NOT draining Diagnostic Checks e Plug not removed from condensate drain e Pinch in condensate drain line e Blockage in condensate drain line e Drain line has unnecessary P trap CONDENSATE DRAIN DIAGNOSTICS Drain Line Ensure you removed the condensate protection plug located at bottom of unit Check your condensate drain line for internal or external blockage Make sure drain line is NOT pinched 59 pU 60 Page SVC 820 Tankless Gas Troubleshooting Manual 31 Error Code Explanation Inlet Thermistor malfunction Diagnostic Checks Inlet Thermistor INLET THERMISTOR DIAGNOSTICS I Screws P nom ie A Qs Bottom of Unit
41. e and flame IS visible while unit is OFF Replace Gas Control Valve 89 90 Page SVC 820 Tankless Gas Troubleshooting Manual 82 Error Code Explanation Control Board Program Chip malfunction Diagnostic Checks e Program Chip PROGRAM CHIP DIAGNOSTICS 5 dd Turn power OFF Verify you have a Program Chip inserted Remove and reinsert Program Chip Attempt to operate in connector A unit again IF unit does NOT display 82 Error Code unit had a loose connection 90 SVC 820 Tankless Gas Troubleshooting Manual Page 91 90 Error Code Explanation The unit detected blockage in the venting during pre purge cycle This Error Code will occur BEFORE unit goes to ignition Possible Causes e VENTING Ba E E E IRL T WE PIE I SE RAT ny aa Se ee ee EU ENT ee Pe oe ee he RE Re SMS ATUM S N I VENTING REFER TO USE amp CARE MANUAL Visually inspect venting for possible blockage and or recirculation of exhaust i 1 Approved Venting Materials 2 Approved Vent Terminations l 3 Vent Lengths i 4 Location Of Vent Termination Recirculation of exhaust 5 Blocked Venting 6 Venting Not Sealed Properly j N N eL o E eat E Dn E er la e a e A h e M M 92 Page SVC 820 Tankless Gas Troubleshooting Manual 92 Error Code Explanation High Efficiency Condensing Units ONLY This is a warning code and unit will continue to operate but will eventually shut down due
42. e unit again NO IF unit continues to display Error Code 10 Replace Control Board YE Press and hold down MAX button on Control Board to activate the blower motor While blower is running test DC voltage across black and blue wires on connector G 4 10 DC VOLTS Attempt to operate unit again If unit continues to display Warning Code 10 Is the DC voltage Control Board and Blower Motor are OK YES OK NO Replace Blower Motor CHECK VENTING amp GAS SUPPLY 31 32 32 Page NOTES SVC 820 Tankless Gas Troubleshooting Manual SVC 820 Tankless Gas Troubleshooting Manual Page 33 11 Error Code Explanation This error code is commonly a result of GAS SUPPLY and or VENTING Flame Rod s does not detect flame This Is caused by the following Inadequate GAS SUPPLY Inadequate VENTING Igniter Rod NOT sparking Build up on Flame Rod s caused by inadequate GAS SUPPLY and or VENTING Gas Valve IMPORTANT If all water heater components test OK you must thoroughly inspect your GAS SUPPLY amp VENTING First Check GAS SUPPLY amp VENTING Diagnostic Checks e GAS SUPPLY amp VENTING e igniter Rod e Flame Rod s e Gas Control Valve M a a t as ee a ey a a M RE e De RSEN d Ra et a T d ee a es a Se Se a EUT S OC NS S N L NO GAS SUPPLY amp VENTING REFER TO USE amp CARE MANUAL Make sure you have sufficient fuel for the unit
43. ed continue to diagnostic chart on next page white wires Attempt to operate unit again High Efficiency ONLY IF 14 Error Code does NOT display unit had a loose connection IF 14 Error Code IS displayed locate the over temp switch and continue to diagnostic chart on next page SVC 820 Tankless Gas Troubleshooting Manual 14 Error Code Diagnostic Chart Turn power OFF and remove Molex connector U Measure resistance between both white wires 50K 500K Ohms Is the resistance to the OHL OK NO YES Reconnect the Molex attempt to operate unit again The OHL has activated due to excessive temperatures This is normally caused by inadequate wrong GAS SUPPLY or inadequate VENTING Check GAS SUPPLY amp VENTING Did the unit shut down due to Error Code 14 Replace Control Board NO Unit had a loose connection operation appears to be normal High Efficiency ONLY Page 51 Mid Efficiency Unit ONLY Replace Unit NO Is this a High Efficiency Unit YES High Efficiency ONLY Check for continuity across the Over Temp Switch Is the continuity OK Replace Over Temp Switch High Efficiency ONLY Replace Unit 52 52 Page NOTES SVC 820 Tankless Gas Troubleshooting Manual SVC 820 Tankless Gas Troubleshooting Manual Page 53 15 Error Code Explanation The hot water temperature and
44. er Motor and reassemble unit Attempt to operate unit again IF 61 Error Code does NOT display Blower Motor needed to be cleaned Turn power OFF Remove 3 screws for Control Board mounting bracket Remove connectors M T amp G Pull Control Board out of way to access Blower Motor Locate Min amp Max buttons on Control Board Continue to diagnostic chart on next page Screws SVC 820 Tankless Gas Troubleshooting Manual Page 75 61 Error Code Diagnostic Chart Remove and reinsert connector G Attempt to operate unit again If the unit malfunctions due to an Error NO Code 61 Test DC voltage across black and red Is the DC voltage wires on Molex connector G OK 144 192 DC VOLTS Replace Control Board YES Press and hold down MAX button on Control Board to activate Blower Motor While Blower is running test DC voltage across black and white wires on Molex connector G 12 18 DC VOLTS Remove and reinsert connector G Is the DC voltage Attempt to operate unit again OK If the unit malfunctions due to an Error Ng Code 61 Replace Control Board YE Press and hold down MAX button on Control Board to activate Blower Motor While Blower is running test DC voltage across black and blue wires on Molex connector G 4 10 DC VOLTS Attempt to operate unit again Replace Blower Motor Is the DC voltage If the unit malfunctions due to an E
45. er heater power cord from 3 prong outlet Disconnect the Remote Control Plug heater back into supply and test heater without Remote Control connected 1 Ensure Blower Motor will turn freely Motor will operate with a small amount Blower Motor um 79 of restriction Current Fault l 2 Check Fan Motor for proper voltage and for water condensation damage 80 1 Ohm Gas Control Valve amp Gas Control Valve 2 Check voltage of all Flame Rods 81 Installation 82 Control Board Is Not Verify Program Chip is installed Programmed Maintenance Installation 90 Clean any blockage in Heat Exchanger Blower Motor inlet flue and exhaust flue Blocked Flue Air Intake Condensing Only Maintenance Warning 92 Replace Neutralizer Neutralizer Needs To Be Replaced Unit Will Still Be Operable Condensing Only Maintenance 93 Replace Neutralizer Neutralizer Must Be Replaced Unit Will NOT Operate Maintenance Installation 1 Clear vent blockages 99 2 Check for blocked Heat Exchanger Blower Motor Cannot Vent SVC 820 Tankless Gas Troubleshooting Manual Condensing ONLY Secondary Stainless Steel Heat Exchanger Condensing ONLY Neutralizer Primary Heat Exchanger Flame Rod s Sight Glass Igniter Rod Igniter Coil Gas Control Valve Water Control amp Bypass Valve Control Board Blower Motor Behind Control Board Heat Exchanger Thermistor Outlet Thermistor Inlet Thermistor Ambient Thermistor COMPONENTS Pa
46. g Venting Not Sealed Properly Gy Ur d UO NER Locate and visually inspect green ground wire connections on lower left side of PCB Ensure the wires are connected properly and not damaged GAS SUPPLY Make sure you have sufficient fuel for the unit to operate properly Gas Type LP or Natural Gas Gas Pressure Gas Pipe Size Gas Flex Line Not To Exceed 36 In Length has the proper ID Inside Diameter and correct BTU rating 5 Gas Regulator 6 GasShut Off Valves 7 Air In Gas Line Du S RENNES Ensure you have a proper ground at power supply to unit 47 48 Page SVC 820 Tankless Gas Troubleshooting Manual FLAME ROD S DIAGNOSTICS flame IS visible V died n m Flame Rod s Remove and reinsert terminals on Flame Rod s Attempt to operate unit again IF 13 Error Code does NOT Turn power OFF Remove and reinsert white connector M and blue connector T on Control Board display unit had a loose connection Indoor Models ONLY 2 Flame Rods Sight Glass Locate sight glass While unit is attempting to ignite determine if flame is touching Flame Rod s IF NO On Remote Control go to Maintenance Mode OY table For Maintenance Mode instructions go to page 16 remove any foreign debris IF foreign debris NOT present CHECK GAS SUPPLY amp VENTING Continue to diagnostic chart on next page SV
47. ge 15 15 16 16 Page SVC 820 Tankless Gas Troubleshooting Manual Maintenance Mode Panel Display The Rheem Tankless has a Maintenance Mode chart on the Remote Control To access the Maintenance Mode turn the unit OFF at Remote Control and make sure water flow is OFF Then hold down the UP and DOWN arrow keys at the same time for 5 seconds You will hear an audible beep and see the display go to 1E By pressing the UP and DOWN arrow keys on the remote thermostat you can access a variety of information about the water heater To activate the unit while displaying the maintenance panel push the power button once open a hot water fixture and the green LED will illuminate This will allow you to access a variety of real time information while the unit is in operation Shortcut Lift dip switch 1 to the up position to go immediately into maintenance mode This can be done while the water heater is in operation While in Maintenance Mode you want to push the up arrow key to select the table you wish to view The table is designated by a letter and is always displayed as the second digit Then push the P d arrow key to display the number item in the table you selected You can select as many as 8 readings for each table To perform diagnostics in this service manual press the up arrow until you get to table 1Y Now using your down arrow you can change the number in front of Y As you move through the diagnostic readings t
48. gulator are sized properly Ensure appliance is properly grounded Check power supply for proper voltage and voltage drops Disconnect and re connect all wiring harnesses on Gas Control Valve and Control Board If gas supply installation maintenance requirements are met Check gas valves for open or short circuits Check flame rod s and flame rod s wiring harness for damage Check PCB Check flame rod s status SVC 820 Tankless Gas Troubleshooting Manual Page 11 13 Indoor ONLY Venting Flame Rod FL 2 Reads Poor Or Improper Combustion Ensure intake and exhaust venting meet all installation requirements diameter vent lengths venting material venting obstructions and all other requirements as described in the Use amp Care manual Make sure exhaust is not recirculating into fresh air intake If venting requirements are met Remove any blockage from venting or from in front of vent termination Verify altitude settings Check Flame Rod FL 2 Check Blower Motor T NE 14 Condensing only Maintenance Flue Temperature Too High Condensing Only 1 Clean blockage in heat exchanger 2 Remove any blockage from Blower Motor and exhaust vent Mid Efficiency amp Condensing Over Heat Limiter OHL Fault Mid Efficiency amp Condensing If Condensing maintenance requirements are met Verify U connector is connected to Control Board Verify wiring harness is connected to O
49. he resistance across 2 black wires on bottom Molex Refer to Data Table below Replace Ambient Thermistor YES Remove Molex from Connector R at Control Board Check continuity from black 3 wire at Molex connector R and black wires at Blue Molex located behind Control Board Check continuity from blue 7 wire at Molex connector R and blue wire at Blue Molex located behind Control Board Replace wiring harness for Connector R on Control Board Is the continuity across all wires OK 64DV 84DV 95DV 7K 23K Ohms fie 64X 84X 95X 2K 72K Ohms H95DV H95X 2K 72K Ohms YES Attempt to operate unit again If the unit malfunctions due to an Error Code 34 Replace Control Board 67 68 Page SVC 820 Tankless Gas Troubleshooting Manual 35 Error Code Explanation Improper Thermistor connection Unit has Diagnostic Checks four Thermistors one or more possibly has a poor Inlet Heat Exchanger Outlet and Ambient connection or not connected in proper location Thermistors THERMISTORS DIAGNOSTICS Turn power OFF Remove and reinsert connector R Turn power OFF Remove connector R on Control on Control Board Attempt to operate unit again IF Board Measure the resistance for all temperature 35 Error Code does NOT display unit had a loose sensors step 3 IF temperature sensor FAILS the connection resistance check go to the appropriate
50. he selected table will flash first and then the diagnostic reading You will see the following as you navigate the Y table OY Flame Rod Status 1Y lt Water Flow in gallons per minute 2Y Ambient air temperature 3Y Water inlet temperature AY Heat exchanger temperature 5Y Hot water outlet temperature 6Y Fan speed x 100 rpm 7Y Power for modulating gas valve 8Y Null no reading 9Y Null no reading FULL MAINTENANCE DISPLAY CHART AVAILABLE ON NEXT PAGE MAINTENANCE INFORMATION TABLE SVC 820 Tankless Gas Troubleshooting Manual Page 17 First Digit Use DOWN arrow key on Remote Control E Null Fault Codes of the most recent 8 faults Null F Null Sequence Number of the most recent 8 faults Null C Total combustion times until recent error fault x 10000times Null 6 S 7 5 D Total combustion times until recent error fault x 100 times Null c 9 9 H Total combustion period until recent error fault x 1000 hours Null o E e J Total combustion period until recent error fault x 10 hours Null 5 gt y bU E E E e S 3 5 c 2 o O y c S E zn 2 E o g 2z x 2 s c5 3 a qs z c gt B 9 FC os L ees 90 2e m R 5 8S2 29595 Ya We 3 3 a E 2 Dx cor oo o G Pe 3 2 2 5 oun o co z o x t o o E o ac n S ca 2 Go 2 o e S E m amp v p 2 2 le 2 o E o oO o E a tie
51. hecks water temperature is above the set point on Remote 1 Outlet Thermistor Control 2 Water Bypass Valve Check the Outlet Thermistor FIRST OUTLET THERMISTOR DIAGNOSTICS Ty xs ij esr rl O NA Turn power OFF Remove connector R on Control Board Measure resistance between Black 3 amp red 4 wires 7K 23K Ohms IF OK attempt to operate Bottom of Unit unit again IF 16 Error Code does NOT display unit had a loose connection Turn power OFF Remove 3 screws for Control Board mounting bracket Remove connectors M T amp IF resistance tested OK and 16 Error Code IS G Pull control board out of way to access BLACK displayed go to Error Code 66 for Water Bypass Valve Molex for Outlet Thermistor located near the Blower diagnostics IF resistance NOT OK go to step 2 Motor Molex Connectors Separate top and bottom of BLACK Molex for Outlet Thermistor Top of Molex has 2 black wires and 1 red wire Bottom of Molex has 2 black wires Continue to diagnostic chart on next page Outlet Thermistor SVC 820 Tankless Gas Troubleshooting Manual Page 55 16 Error Code Diagnostic Chart Clean Outlet Thermistor Retest Thermistor IF tests OK the water heater appears to be normal attempt to operate Check the resistance across 2 black wires Is the resistance to the Outlet Thermistor OK on bottom Molex NO unit again IF resistance NOT OK 7k
52. http waterheatertimer org Troubleshoot Rheem Tankless water heater html yo RUUD RES RHEEM MANUFACTURING COMPANY Tankless Gas Troubleshooting Manual SVC 820 Mid amp High Efficiency Platform The purpose of this manual is twofold it serves as a training tool as well as a troubleshooting manual for qualified installers and service technicians Technical Support 800 432 8373 www rheem com 2 Page SVC 820 Tankless Gas Troubleshooting Manual TABLE OF CONTENTS General Information Specifications 3 Shutdown Sequence Error Code Ta Components Callouts Maintenance ble Mode How To Control Board Callouts Reset Procedure Error Code Diagnostics No Error Code amp No Hot Water P1 Warning Code 1L Warning Code 03 Error Code 05 Warning Code 10 Warning Code 11 Error Code Flame Gas Control Valve Spark IS visible Flame is NOT visible Rod Flame IS visible eee Control Board 12 Error Code Gas Supply amp Venting Flame 13 Error Code Flame 14 Error Code 15 Error Code 16 Error Code 24 Error Code 29 Error Code 31 Error Code 32 Error Code a M HUE S O ON n Un A 22 23 24 25 26 29 33 33 34 36 38 40 43 43 44 47 47 47 48 50 53 54 56 59 60 62 33 Error Code 34 Error Code 35 Error Code 51 Error Code 52 Error Code 61 Error Code 65 Error Code 66 Error Code 71 Error Code 72 Error Code 76 Error Code 79 Error Code 80 Error Code 82
53. iagnostic Chart Turn power OFF Unplug unit and plug back in Turn power ON While viewing burner chamber through sight glass turn on water flow to begin ignition sequence Is there a visible flame before Igniter Rod sparks YES Visibly inspect burner chamber through sight glass On Remote Control go to Maintenance Mode OY table For Maintenance Mode NO Is debris visible on burner assembly YES Remove and clean burner assembly NO instructions go to page 16 All Maintenance Mode OY readings should be done immediately after turning Indoor Units 05 Outdoor Units 01 the unit ON IF flame sensor IS detecting flame Maintenance Mode will display N AN Does OY Statusin y ge Maintenance Mode N indicate presence X of flame Turn power OFF Unplug unit Disconnect Molex connector s from Flame Rod s Plug unit in Turn power ON Turn water flow ON to begin ignition sequence P N ON yt Does OY Status in PA Maintenance Mode N lt indicate presence S of flame Attempt to operate again If unit displays 72 Error Code Replace Control Board Attempt to operate again If unit displays 72 Error Code and flame IS visible while unit is OFF Replace Gas Control Valve Page 83 re Nen Water heater appears to be normal Attempt to operate again Clean or Replace Flame
54. ign debris IF foreign debris NOT present CHECK GAS SUPPLY amp VENTING Continue to diagnostic chart on next page SVC 820 Tankless Gas Troubleshooting Manual Page 37 FLAME ROD s Diagnostic Chart Attempt to operate unit again Cycle unit ON and check AC Volts at white M amp blue T connectors Is the AC voltage OK IF unit malfunctions due to Error Code 11 NO 1 100 AC VOLTS Replace Control Board YES Cycle unit ON while in Maintenance Mode check Flame Rod status under table OY IF detecting flame Maintenance Mode will display Indoor Models 05 Outdoor Models 01 Remove and clean Flame Rod s Attempt to operate unit again Is Flame Rod s IF Flame Rods still does not detect flame i detecting flame NO Replace Flame Rod s YE Attempt to operate unit again If the unit malfunctions due to an Error Code 11 Flame Rod s are OK CHECK GAS VENTING amp GROUND 37 38 Page SVC 820 Tankless Gas Troubleshooting Manual GAS CONTROL VALVE DIAGNOSTICS Igniter Rod DOES spark amp NO flame Turn power OFF Remove and reinsert connector K on Remove and reinsert connector R on Control Board Control Board Locate PGFR valve on lower right of unit Remove and reinsert Molex connector with red wire and Molex IF 11 Error Code does NOT display unit had a loose connector with black wire on PGFR connection Attempt t
55. nit had a loose connection 80 SVC 820 Tankless Gas Troubleshooting Manual Page 81 71 Error Code Diagnostic Chart Attempt to operate again While unit is attempting to go to ignite Is the DC voltage If the unit malfunctions due to an Error check DC voltage across yellow and black OK Code 71 wires on Molex connector K 75 100 DC VOLTS Replace Control Board Reset the water heater and attempt to operate again If the unit malfunctions due to an Error Code 71 Replace Gas Control Valve 81 82 Page SVC 820 Tankless Gas Troubleshooting Manual 72 Error Code Explanation Flame Rod s malfunction Flame Rod s is detecting the presence of flame BEFORE igniter is activated Diagnostic Checks e Flame Rod s e Gas Control Valve FLAME ROD s amp GAS CONTROL VALVE DIAGNOSTICS Turn power OFF Remove and reinsert white connector M and blue connector T on Control Board Sight Glass Gas Control Valve Flame Rod s Remove and reinsert terminals on Flame Rod s Attempt to operate unit again IF 72 Error Code does NOT display unit had a loose connection Indoor Units ONLY 2 Flame Rods Visually inspect Gas Control Valve wiring harnesses for loose connections or damaged wiring Gas Control Valve is located on lower right side of unit Locate Sight Glass Continue to diagnostic chart on next page SVC 820 Tankless Gas Troubleshooting Manual 72 Error Code D
56. ntrol Valve malfunction The unit Diagnostic Checks detects the presence of flame when the demand for hot e Flame Rods s water is terminated and burner is OFF This error code e Gas Control Valve will only occur at time of shut down FLAME RODS amp GAS VALVE DIAGNOSTICS Flame Rod s Turn power OFF Remove and reinsert white Remove and reinsert terminals on Fame Rod s connector M and blue connector T on Control Attempt to operate unit again IF 51 Error Code does Board NOT display unit had a loose connection Indoor Models ONLY 2 Flame Rods Sight Glass Visually inspect Gas Control Valve wiring harnesses for loose connections or damaged wiring Gas Control Valve is located on lower right side of unit Locate sight glass Continue to diagnostic chart on next page Gas Control Valve SVC 820 Tankless Gas Troubleshooting Manual Page 71 51 Error Code Diagnostic Chart N U On Remote Control go to Maintenance Mode OY table For Maintenance Mode instructions go to page 16 While viewing burner chamber through sight glass All Maintenance Mode OY readings should be done immediately after turning the unit OFF IF Flame Rod s is In 10 second intervals cycle the water detecting flame Maintenance Mode will display heater 3 times by turning unit on off on off on off Indoor Units 05 Outdoor Units 01 N N S Ee ae ee a EEP E FE A A E E a we S N P
57. nual Page 9 Error Code Code Fault Remedy j 5 Flow Rate Maintenance 1 Increase water flow rate or set higher temperature Nothing Happens When 2 New Installations Ensure hot and cold water lines are not crossed Ez Water Is Flowing Through 3 Check for plumbing crossover in the home Unit Control Board 4 Clean water inlet filter Displays Water Temp 5 Check water flow sensor may be jammed P1 Maintenance Warning Check hot water tap flow clean aerator if necessary Clean water inlet filter Water Flow Too Low I hoes op Increase flow rate or set higher temperature Unit Will Still Be Operable Minimum Flow f maintenance requirements are met 0 4 GPM To Activate 35 AT 1 Check water flow sensor Maintenance 1L Water Heater Has ied neat EXC en efr l Buildup Of Lime Scale High Altitude Installations ensure proper altitude settings have been made Deposits Check communications cable connection 03 MIC 185 MIC 6 amp EZ Link 2 Check 4 dip switch setting is in the ON position Dip Set 1 Top Dip switch 4 on the water heaters only Maintenance Warning 1 Remove any vent blockage Make sure venting meets all installation requirements Air Intake Or Vent Exhaust May Be Blocked f maintenance requirements are met Unit Will Still Be Operable 1 Check fan motor 05 Installation Warning The vent Pipes On The Vent Termination May Not Be Connected Unit Will Still Be Ope
58. o operate unit again IF 11 Error Code IS displayed continue to diagnostic chart on next page SVC 820 Tankless Gas Troubleshooting Manual Page 39 GAS CONTROL VALVE Diagnostic Chart Attempt to operate unit again While unit is attempting to ignite check Is the DC voltage OK IF the unit malfunctions due to an Error NO Code 11 DC voltage across red wire 1 and black wire 2 on connector R 1 5 14 DC VOLTS Replace Control Board YES Turn unit OFF remove Molex connector R Measure resistance across red wire 1 and black wire 2 on Molex connector R 40 80 Ohms Remove and reconnect terminals on PGFR Attempt to operate unit again IF unit malfunctions due to Error Code 11 Is the resistance Of NO Replace Gas Control Valve YE PGFR is OK Continue to next page 39 40 40 Page SVC 820 Tankless Gas Troubleshooting Manual GAS CONT ROL VALVE Diagnostic Chart U Turn unit OFF and remove Molex connector 1 1 Nem Se K to measure resistance s Measure resistance across black wire 46 and yellow wire 1 on Molex connector Is the K resistance OK Replace Gas Control Valve 0 8k 2 4k Ohms Measure resistance across black wire 6 Is the resistance OK and white wire 2 on connector K Replace Gas Control Valve 0 8k 2 4k Ohms Measure resistance across black wire
59. or current fault The unit detected a fault with the Blower Motor Diagnostic Checks e Blower Motor BLOWER MOTOR DIAGNOSTICS 2 Turn power OFF Remove and reinsert connector G on Control Board Attempt to operate unit again IF 79 Error Code does NOT display unit had a loose connection Remove 3 screws holding Blower Motor in place Clean Blower Motor and reassemble unit Attempt to operate unit again IF 79 Error Code does NOT display Blower Motor needed to be cleaned Bottom of Unit Turn power OFF Remove 3 screws for Control Board mounting bracket Remove connectors M T amp G Pull Control Board out of way to access Blower Motor Locate Min amp Max buttons on Control Board Continue to diagnostic chart on next page SVC 820 Tankless Gas Troubleshooting Manual Page 87 79 Error Code Diagnostic Chart Remove and reinsert connector G Attempt to operate unit again IF the unit malfunctions due to an Error NO Code 79 Test DC voltage across black and red Is the DC voltage wires on Molex connector G OK 144 192 DC VOLTS Replace Control Board YES Press and hold down MAX button on Control Board to activate Blower Motor While Blower is running test DC voltage across black and white wires on Molex connector G 12 18 DC VOLTS Remove and reinsert connector G Attempt to operate unit again If the unit malfunctions due to an E
60. or heat exchanger temperature reached 207 degrees F for more than 15 seconds IMPORTANT Inadequate GAS SUPPLY and or VENTING will create hot spots in the heat exchanger Diagnostic Checks e GAS SUPPLY amp VENTING e Sediment Build Up in Heat Exchanger e Heat Exchanger Temperature Sensor ee ee Ee Ee EE e e e GAS SUPPLY amp VENTING I REFER TO USE amp CARE MANUAL Make sure you have sufficient fuel for the unit to operate properly 1 Gas Type LP or Natural Gas Gas Pressure Gas Pipe Size Gas Flex Line Not To Exceed 36 In Length has the proper ID Inside Diameter and correct BTU rating Gas Regulator Gas Shut Off Valves Air In Gas Line Se es Visually inspect venting for possible blockage and or recirculation of exhaust 1 Approved Venting Materials Approved Vent Terminations Vent Lengths Location Of Vent Termination Recirculation of exhaust Blocked Venting Venting Not Sealed Properly C Si O SEDIMENT BUILD UP DIAGNOSTICS Go to Error Code 1L for flushing instructions HEAT EXCHANGER THERMISTOR DIAGNOSTICS Go to Error Code 32 for Heat Exchanger Thermistor diagnostic instructions 54 Page SVC 820 Tankless Gas Troubleshooting Manual 16 Error Code Explanation Outlet water temperature is too hot The Diagnostic C
61. r OF 9 go s I roe 53 S 17A 5 9 a w o 2 2 O vw o e c qc E e O o 259 9 o 9 t o c OS c t gt E E Kd 5 o c 9 c 3 3 3 3 3 3 o 3 72 Z Oa uw A gt wo z 2 Z z oz 17 18 18 Page SVC 820 Tankless Gas Troubleshooting Manual CONTROL BOARD Color Picture Each letter indicates the connector identifier SVC 820 Tankless Gas Troubleshooting Manual Page 19 CONTROL BOARD fososecaccy DIP 1 Adjust max temperature EZ Link cable DIP 2 Adjust for altitude differential MIN amp MAX Adjust water temperature setting gas pressure etc ADJ Adjust gas pressure etc M Flame Rod for all models detects flame T Flame Rod for indoor models only monitors combustion efficiency F Communication port manifold installations A Fuel type and temperature Program Chip U Over Heat Limiter OHL R Thermistors Ambient Inlet Outlet Heat Exchanger amp Modulating Gas Valve PFGR S Water Flow Sensor C Water Control Valve B Water Bypass Valve V Remote Control Main Bath G Blower Motor K Gas Control Valve H Igniter Rod 19 20 20 Page NOTES SVC 820 Tankless Gas Troubleshooting Manual SVC 820 Tankless Gas Troubleshooting Manual Page 21 RESET PROCEDURE ONLY for Hard Lockouts Error Codes 13 92 93 99 L 2 3 Turn Remote Control OFF leave unit plugged in Remove Front Cover Locate the Dip Switche
62. rable Make sure all venting is properly sealed and meets all venting requirements diameter vent lengths venting material venting obstructions and all other installation requirements as described in installation manual If installation requirements are met 1 Check Blower Motor 10 10 Page SVC 820 Tankless Gas Troubleshooting Manual Maintenance Clean any blockage in venting Blower Motor air intake 10 If maintenance requirements are met Decrease Of Ventilation Amount Blower Motor Check Blower Motor 11 Installation Gas supply Ignition Failure Seo o7 qr HS ah Ensure you have gas to the appliance and valves are turned ON Ensure gas type gas pressure and gas volume are correct Bleed all air from gas lines Ensure gas line meter and regulator are sized properly Ensure appliance is properly grounded If installation gas supply requirements are met Check Gas Control valve for open or short circuits Ensure Igniter Rod is operational Check igniter Flame Rod s and Igniter Flame Rod s wiring harness for damage Check Control Board Check Flame Rod Status 12 Gas supply Installation Maintenance Flame Failure Had Main Burner Then Lost It Q9 Spy MY cb 399 NI TES WN Ensure gas type and pressure is correct Bleed all air from gas lines Ensure Flame Rod wire s is connected Check Flame Rod s for carbon build up Ensure gas line meter and re
63. rror NO Code 79 Is the DC voltage OK Replace Control Board YE Press and hold down MAX button on Control Board to activate Blower Motor While Blower is running test DC voltage across black and blue wires on Molex connector G 4 10 DC VOLTS Attempt to operate unit again Replace Blower Motor Is the DC voltage If the unit malfunctions due to an Error OK Code 79 YES NO Replace Control Board 87 88 Page SVC 820 Tankless Gas Troubleshooting Manual 80 Error Code Explanation Gas Control Valve malfunction The unit detects the presence of flame when the demand for hot water is terminated and burner is OFF This error code will only occur at time of shut down Diagnostic Checks e Flame Rod s e Gas Control Valve FLAME ROD s amp GAS CONTROL VALVE DIAGNOSTICS Turn power OFF Remove and reinsert white connector M and blue connector T on Control Flame Rod s Remove and reinsert terminals on Flame Rod s Board Attempt to operate unit again IF 80 Error Code does Sight Glass Gas Control Valve NOT display unit had a loose connection Indoor Units ONLY 2 Flame Rods Visually inspect Gas Control Valve wiring harnesses for loose connection or damaged wiring Gas Control Valve is located on lower right side of unit Locate Sight Glass Continue to diagnostic chart on next page SVC 820 Tankless Gas Troubleshooting Manual Page 8
64. rror OK Code 61 YES NO Replace Control Board 75 76 Page SVC 820 Tankless Gas Troubleshooting Manual 65 Error Code Explanation Water Control Valve malfunction Diagnostic Checks e Water Control Valve WATER CONTROL VALVE DIAGNOSTICS Bottom of Unit Turn power OFF Remove and reinsert connector C on Control Board Attempt to operate unit again IF Turn power OFF Remove 3 screws for Control Board 65 Error Code does NOT display unit had a loose mounting bracket Remove connectors M T amp a connection G Pull Control Board out of way to access Water Control Valve Water Control Valve Visually inspect Water Control Valve wiring harness for loose or damaged terminals Itis located right of the Top of Unit Blower Motor connected directly to the water inlet Reassemble unit and Bottom of Unit continue to diagnostic chart on next page Blower Motor SVC 820 Tankless Gas Troubleshooting Manual Page 77 65 Error Code Diagnostic Chart Attempt to operate unit again While water is flowing and unit is attempting to ignite check DC Voltage across White amp Black Wires at connector C Is the DC voltage OK If the unit malfunctions due to an Error NO Code 65 Replace Control Board 8 16 DC VOLTS YES Turn power to unit OFF then ON again and turn water flow on Check DC Voltage across Red amp Black Wires at connector C 8 16 DC VOLT
65. s Upper Right on the Control Board Make sure all the Dip Switches are OFF down position Locate Dipl Switch 2 and turn it ON up position then immediately turn it off Within 5 seconds press and hold the MIN and MAX buttons for at least 2 seconds The Remote Control will flash UL then it will go solid This indicates the heater has been reset Release the buttons Turn Remote Control ON You may operate unit asses ha CLEARING FAULT HISTORY PROCEDURE L Turn Remote Control OFF leave unit plugged in Remove Front Cover Locate the Dip Switches Upper Right on the Control Board Make sure all the Dip Switches are OFF down position Locate Dipl Switch 1 and turn it ON up position then immediately turn it off Within 5 seconds press and hold the MIN or MAX button for at least 2 seconds The Remote Control will flash CL then it will go solid This indicates the fault history has been cleared Release the buttons You can verify clearing history by entering Maintenance Mode and check the code at location 1E Should read NULL two dashes Turn Remote Control ON You may operate unit 21 22 22 Page SVC 820 Tankless Gas Troubleshooting Manual No Error Code amp No Hot Water Remote Control Displays Hot Water Temperature Setting Explanation No hot water is delivered when water is flowing through unit and Remote Control display
66. s the hot water temperature setting Possible Causes e Water Flow Minimum flow of 0 4 GPM to activate e DIP 1 Setting On Main Control Board PCB e Water flow sensor Water Flow 1 Turn OFF water supply to unit Turn Remote Control OFF unplug power cord at wall outlet Wait 10 seconds plug power cord back into outlet wait 20 seconds turn the Remote Control ON Turn water supply ON check the nearest hot water fixture for hot water If you have hot water then the unit needed to be reset 2 Water flow might be too low Open multiple hot water fixtures If unit fires then there is not enough water flow to engage the unit at a particular fixture Check your fixture aerator screen s for debris Clean if necessary 3 Your water flow may be restricted by debris in Water Filter Remove the water filter and inspect Clean if necessary 4 Your water lines might be crossed Make sure your hot and cold water supply lines are connected to the appropriate hot and cold water assembly connections on the unit Dip 1 Setting DIP 1 All Dip 1 switches must be in the OFF position Manifold Units ONLY Go to Error Code 03 to verify proper DIP 1 setting As set from factory Water Flow Sensor FINAL CHECK The water flow sensor in the water volume control valve Check connector S between the Red and Black With the unit ON and no water flow you should be 11 17 DC volts If not replace the PCB IF you have voltage then
67. ss for loose or damaged connections Modulating Valve 2 Ohm PGFR Valve 1 Ensure Blower Motor will turn freely Motor will operate with a small amount Installation Maintenance f mer of restriction 2 Check wiring harness to Motor for damaged and or loose connections Blower Motor 3 Check venting length not to exceed max lengths and bends Check Water Control Valve wiring harness for loose or damaged terminals 65 Water Control Valve 2 Check for proper voltage to Water Control Valve 1 Check Water Bypass Valve wiring harness for loose or damaged terminals 66 Water Bypass Valve 2 Check for proper voltage to water by pass solenoid Check Gas Control Valve wiring harness for loose or damaged terminals 71 Gas Control Valve Ohm Gas Control Valve 1 Ensure Flame Rod s is touching flame when unit fires 2 Checkinside burner chamber for any foreign material blocking flame at Flame Flame Rod Rod s 72 Detected False Flame 3 Checkall wiring to Flame Rod for damage Check Flame Rod for proper voltage 5 Remove Flame Rod and check clean with steel wool Do not use sandpaper 13 14 14 Page SVC 820 Tankless Gas Troubleshooting Manual 1 Check Remote Control wiring for loose or damaged connections 2 Bypass Remote Control connect Remote Control directly to remote 36 Communication Fault connection at bottom of the heater Replace cable if found to be faulty With Remote Control 3 Remove wat
68. the gas volume in order to maintain the outlet temperature The water flow sensor also adjusts the proper amount of cold water mix flow to supply a stable hot water temperature at all times A signal is also sent to the Blower Motor in order to constantly maintain the correct proportion between gas and air volumes The PCB is constantly monitoring all of these inputs and actions to ensure the outlet water temperature is within 1 5 degrees of thermostat setting It also monitors the BTU required to heat the cold water to the thermostat setting and adjusts the gas valve accordingly Indoor Models Only When the air intake is blocked or oxygen is not sufficient the output of the Flame Sensor changes The PCB senses this change and controls the Fan and Gas Valve in order to prevent imperfect combustion If the PCB cannot correct such condition the unit will go into an error code When the hot water tap is closed the flow rate signal from the water flow sensor stops Gas valve is closed Main burner shuts off The Fan continues to run for a few minutes Purpose is to cool the heat exchanger exhaust all combustions gases and to maintain the burner chamber charged with air for immediate ignition if there is another hot water demand SEQUENCE OF OPERATIONS 1 Ignition Sequence 2 Monitoring Sequence 3 Shutdown Sequence Open Hot Water Tap Up amp Down 24 Activated
69. tinue to diagnostic chart on next page Blower Motor Screws SVC 820 Tankless Gas Troubleshooting Manual Page 79 66 Error Code Diagnostic Chart Attempt to operate unit again Turn Remote Control OFF unplug unit Is the DC voltage OK If the unit malfunctions due to an Error NO Code 66 and then ON again Check DC voltage across red and black wires on Molex connector B 8 16 DC VOLTS Replace Control Board YES While Water Bypass Valve is operating water is flowing check DC voltage across red and black wires at Water Bypass Valve wiring harness 8 16 DC VOLTS Attempt to operate unit again Is the DC voltage OK If the unit malfunctions due to an Error NO Code 66 Replace Control Board YE Attempt to operate unit again If the unit malfunctions due to an Error Code 66 Replace Water Bypass Valve 79 80 Page SVC 820 Tankless Gas Troubleshooting Manual 71 Error Code Explanation Gas Control Valve malfunction Diagnostic Checks Gas Control Valve GAS CONTROL VALVE DIAGNOSTICS Gas Control Valve J Visually inspect Gas Control Valve wiring harnesses for loose or damaged terminals Gas Control Valve is located on lower right side of unit Turn power OFF Remove and reinsert connector K on Control Board Attempt to operate unit again IF 71 Error Continue to diagnostic chart on next page Code does NOT display u
70. tion Communication failure between water heaters remote control and or manifold controller Diagnostic Checks e DIP1 Setting On Main Control Board PCB DIP 1 SETTING Manifold units only DIP 1 switch 4 must be in the ON position for each unit Check ALL Molex connections on ALL Control Boards Control Board Layout for third generation models Dip Switch Adjustment Top Set Connector F DIP 1 Number 4 Switch in the ON Position Wire Clamp If Error Code 03 is displayed after completing all checks Call Technical Support 800 432 8373 25 26 Page SVC 820 Tankless Gas Troubleshooting Manual 05 Warning Code Explanation The Flame Rod has detected improper burner combustion The unit is NOT able to maintain the proper fuel air mixture for proper combustion This warning code is commonly caused by VENTING and or GAS SUPPLY The unit will continue to operate and attempt to resolve improper combustion but may eventually shut down with an error code 11 12 or 13 Diagnostic Checks e GAS SUPPLY amp VENTING e Dip 2 Setting On Printed Circuit Board PCB CLEA Iee I e GAS SUPPLY amp VENTING REFER TO USE amp CARE MANUAL Make sure you have sufficient fuel for the unit to operate properly 1 Gas Type LP or Natural Gas Gas Pressure Gas Pipe Size Gas Flex Line Not To Exceed 36 In Length Has The Proper ID Inside Diameter amp Correct BTU
71. to an error code 93 REPLACE NEUTRALIZER ASAP Once Neutralizer is replaced follow reset procedures on page 21 93 Error Code Explanation High Efficiency Condensing Units ONLY Unit will NOT operate until the Neutralizer is replaced REPLACE NEUTRALIZER IMMEDIATELY Neutralizer rocks made from Calcium Carbonate CACO3 Neutralizer Kit may be ordered through Rheem Supplier Once Neutralizer is replaced follow reset procedures on page 21 SVC 820 Tankless Gas Troubleshooting Manual Page 93 99 Error Code Explanation The unit detected blockage in the venting during post purge cycle Blockage was detected when the demand for hot water terminated and burner was OFF This error code will only occur at time of shut down Unit must be reset by performing reset procedure on page 21 Possible Causes e Venting I VENTING REFER TO USE amp CARE MANUAL Visually inspect venting for possible blockage and or recirculation of exhaust 1 Approved Venting Materials 2 Approved Vent Terminations 3 Vent Lengths 4 Location Of Vent Termination Recirculation of exhaust 5 6 Blocked Venting Venting Not Sealed Properly Sa a ees a pc ce Ys 93 94 Page SVC 820 Tankless Gas Troubleshooting Manual Diagnostic Points on Printed Circuit Board Measurement Point Normal Value What you are checking Connection Wire Color I J AC 108 132V Do you have po
72. unit Maintenance M Impe 4 Clean air inlet screen Neutralizer Is clogged 5 Clean heat exchanger fins If maintenance requirements are met 29 1 Check neutralizer water level electrode Mid Efficiency amp Mid Efficiency amp Condensing Condensing 1 Clean air inlet screen Clean heat exchanger fins Maintenance Heat Exchanger Temperature Is Too Low 1 Check Thermistor wiring for damage 31 Inlet Thermistor 2 Checkand clean scale from Thermistor 3 Ohm Thermistor 1 Check Thermistor wiring for damage Heat Exchanger 32 j 2 Check and clean scale from Thermistor Thermistor 3 Ohm Thermistor 1 Check Thermistor wiring for damage 2 Checkand clean scale from Thermistor 33 Outlet Thermistor 3 Ohm Thermistor SVC 820 Tankless Gas Troubleshooting Manual Page 13 1 Check Thermistor wiring for damage 2 Checkand clean Ambient Thermistor 3 Ohm Thermistor 34 Ambient Thermistor Bb d If wiring and component readings are normal Check for restrictions in airflow around unit and vent terminal Ensure fan blade is tight on motor shaft and spins freely 1 Checkthat all Thermistors are secured to proper connections on Control 35 Improper Thermistor Board Connection 2 Checkthat all quick connectors between Control Board and Thermistors 1 Check Gas Control Valve wiring harness for loose or damaged terminals 51 Gas Control Valve Ohm Gas Control Valve T PGFR Valve 1 Check PGFR Valve wiring harne
73. wer to the control board U W1 W2 50K Q 500K Q Is the Over Heat Film Wrap OK DC 2 5V pulse Does the water flow sensor send a pulse BR1 BK2 More than 1 310 f Only when water is flowing thru control S pulses minute Does the water flow sensor have voltage R3 BK2 DC11 17V Power ON no water flow BK4 R6 DC 144 192 V Does the fan motor have the proper voltage G W3 BK4 DC12 18V Does the fan motor have proper voltage BL1 BK4 DC 4 10 Pulse Is the fan motor producing a regular pulse 68 F 10 3 KO R W6 BK3 Is the Inlet Thermistor working 104 F 4 9 KO Y5 BK3 68 F 10 3 KO R EL Sas Is the Heat Exchanger Thermistor working onaensing K Ur _ aaa 104 F 4 9 KO 68 F 10 3 KO R R4 BK3 Is the Outlet Thermistor working 104 F 4 9 KO SVC 820 Tankless Gas Troubleshooting Manual Page 95 All Mid Efficiency Indoor Units ONLY 68 F 10 3 KO 104 F 4 9 KO BI7 BK3 All Outdoor amp All Condensing Is the Ambient Thermistor working Units ONLY 68 F 6 2 KO 104 F 2 6 KO DC1 5 14V Is the P G F R valve operating R1 BK2 40 800 Proportional Gas Flow Regulating Valve W1 GND AC 1 100 V Flame Rod s detecting flame BL1 GND AC 1 100 V GY3 GYA AC 108 132V Is the igniter working properly DC90 120V Y1 BK6 Gas Inlet Solenoid Valve Okay 0 8 2 4 KO DC90 120V W2 BK6 Solenoid Valve 1 Okay 0

Tankless Gas Troubleshooting Manual SVC 820

Contents

Download Pdf Manuals

Related Search

Related Contents