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A.O. Smith 100 Series Instruction manual

1. 47 CCB Cover Removal And 48 CCB Circuit Board Layout iiiter enter t iterare 49 CCB Connection Identification eese 50 WIRING DIAGRAM SUF 60120 THRU 100250 52 WIRING DIAGRAM SUF 119300 THRU 119500 53 CONTROL OVERVIEW cru Rock erede ec bebe 54 INTRODUCTION This Service Handbook covers the water heater Model and Series numbers listed on the front cover only The instructions and illustrations contained in this service handbook will provide you with troubleshooting procedures to verify proper operation and diagnose and repair common service problems QUALIFICATIONS QUALIFIED INSTALLER OR SERVICE AGENCY Installation and service of this water heater requires ability equivalent to that of a Qualified Agency as defined by ANSI below in the field involved Installation skills such as plumbing air supply venting gas supply and electrical supply are required in addition to electrical testing skills when performing service ANSI Z223 1 2006 Sec 3 3 83 Qualified Agency Any individual firm corporation or company that either in person or through a representative is engaged in and is responsible for a the installation testing or replacement of gas piping or b the connection installation testing repa
2. 8 OC OC O J15 Socket Pressure Switches ene BEscmPHON J16 Socket Low Voltage In Ne BEScRPHON O 6 Grounding S O Servicing should only be performed by a Qualified Service Technician 51 WIRING DIAGRAM SUF 60120 THRU 100250 Blower T White Brown 2 White Blue 4 Wite Orange erreen igna Neutral f gt Brown Neutral m TA to Spark Blue tant Hit lt rH 2 31505 SMO 4 White Gre en Jamogd Splice 1 Black fi Splice Teen vr Upper Temperature Probe SECO OUT to blower No factory connections 120V Central Control Board CCB PIs SBeyoA PIEN CCB JS pper Probe Outlet Pressure Lower Switch Temperature Probe ret Inlet Pressure M Switch Blower Prover Pressure Switch E Wire Green 5 Orange A Blue Lu m 8 L 7 WhiteiBlue SBEIIGA gir ao
3. Drive enable 3 White Yellow 2 White Black Dgnd 1 White Green 120v VFD 1 Blue Jig 3 White Black 4 Yellow Speed Fbad Yellow 2 While Green iT zs BLOWER FEEDBACK 1 Blue 7 White Junction Box 3 Black Neutral mmon fact eed Fact ind enable 98 aweien D Qo f T Wihite Yellow Drive enable No factory connections 8BE3IGA EER led Central Control Board 2 CCB J6 120V Out ick L Ht lt Blue Neutral t gt gt Brown Upper Temperature Probe SECO m E White Green L9 Orange 4 blue CCB JG Upper Probe 2 White Blue TWhlte Fed Outlet Pressure Lower Switch Temperature Probe hie U SBE3IGA MG i Red TIEpuosss Enable Disable Switch Thermistor Thermisior hiet Pressure Hi Switch CCB
4. CCB 210 Lower Probe Lg Telum Prover power EnableiDisable Switch let retum Thiet power rover reim ower Switches CCB J15 Pressure D Anode 77 Junction Box Connects Anode fto bumer Yellow 2 Green bolt lame LCS Yellow gr condensate 4 Black Condensate 5 black Green m Field Box HIGH Voltage J1 ujeBeoA iras CCBJ14 Limit String Black Fe Ground Bar Gee Vh i L L ie Beas vane Gas Pressure mm Ji Switch Display ARE an guration 3 W2 Green Key Wr Red Display AIN 12 NIY Ae dsa err aoa CCS Configuration Key 18AWG AWM wire 105 C 600V UL style 1015 Flame rod wire 200 C 300V UL 1180 mm m multi conductor power limited cable 18AWG 80 C 300V UL category QPTZ mmm Spark ignition wire 220 C 25kVDC 8mm EMI suppression 52 Servicing should only be performed by a Qualified Service Technician WIRING DIAGRAM SUF 119300 THRU 119500 WD 24v enable
5. Configuration Key Servicing should only be performed by a Qualified Service Technician Key 53 CONTROL OVERVIEW Interaction with the water heater controller is through an UIM display called the User Interface Module UIM This screen is also referred to as the desktop or desktop menu Up and down buttons and three operation buttons allow navigation through the control menus and to make adjustments to the water heater Operation of the three lower buttons is defined immediately above them on the screen While the water heater is operating the user interface will display the UIM screen if there are no active faults or warnings An example of this screen is shown below e first temperature on this screen is the temperature of the water inside the tank e The second temperature on this screen is the Operating Set Point The Operating Set Point is the temperature at which the water heater will maintain the water inside the tank The third line on the screen is a text description of the Operational State of the water heater The operational state of the water heater is also indicated graphically by status icons UIM User Interface Module LCD Screen MANUFACTURER MODEL INFORMATION 4 Title Bar Tank Temperature 103 F Operating Set Point 120 F Status Heating Information Display Status Icons Up amp Down buttons navigate menus adjust user settings
6. Most of the water heater s components such as the Spark Igniter Combustion Blower 24 Volt Gas Control Valve and Temperature Probe are directly connected to one of the CCB s socket connectors Power Supply Board CCB Circuit Board ZA Ee Temperature Probe Connectors Power Transformer Front Cover On Front Cover Removed Servicing should only be performed by a Qualified Service Technician 47 CCB COVER REMOVAL AND REPLACEMENT The cover on the CCB enclosure must be removed for various service procedures outlined in this Service Handbook Refer to the instructions below when removing and replacing the CCB cover Wiring to and from the CCB and other water heater components enters the CCB enclosure on the bottom Removing the enclosure cover is a simple procedure Care must be taken when replacing the CCB cover to ensure the wiring is routed properly and the cover is replaced correctly Follow the procedures below to ensure the wiring is not pinched or damaged and no connectors are accidentally unplugged Cover Removal Procedure Refer to CCB section on Page 47 for these instructions 1 Ensure power to the water heater is turned off 2 Remove the upper and lower temperature probe connectors 3 Unlock clips on both sides and remove the cover Cover Replacement Procedure 1 Follow Cover Removal Procedure in reverse order to replace cover Service Notes If any operational problems fault conditions or Control Syst
7. TOP VIEW SUF 60120 100250 MODELS Junction Box Powered Anode Assembly Short SUF 100150 100250 odels Only Burner Blower Assembly Ignition Control Powered Anode Long Blower Prover LZ Swite Label Color Green CCB Assembly N WO Blocked Air A o Intake Switch A Blocked Exhaust Switch Label Color Red Exhaust Condensate Elbow Water Outlet 1 1 2 NPT Upper Temperature Probe Junction Box Assembly Burner Blower Assembly Blower Prover Switch Label Color Green Ignition Control Blocked Air Intake Switch Label Color Blue rowered Anode Short Blocked Exhaust Switc CCB Label Color Red Assembly longs Anode Water Outlet 1 1 2 NPT Exhaust Condensate Elbow Upper Temperature Probe Servicing should only be performed by a Qualified Service Technician 5 SEQUENCE OF OPERATION FLOW CHART Sequence is shown with Enable Disable Switch in the Enable position If tank temperature drops below Operating Set Point minus Differential setting a heating cycle is activated Control System performs diagnostic checks Normal State of all pressure switches and ECO are checked Control System Locks Out Blower Prover pressure switch verified open Displays Fault Msg All other pressure switches and ECO are verified closed Combustion Blower is energized Pre Pur
8. amp 8 cto eti centran 7 HIGH Altitlde ota eo ee mde enis 7 Gas Pressure Specifications Gas Supply Systems Supply Gas Regulator tee di ee 8 Gas Pressure Test ertet dee e 9 2 Blower Operation 11 Pressure SWItChes crine a eren etre rena 11 Control System Monitorings 11 Pressure Switch Tests ener eo ettet 12 Continuity Test During 12 Continuity Test During Operation 13 Pressure Test During 13 Press re Switch Settings erret pae 14 3 Blower Prover Open rrr e reci Renier 5 Blocked Air Intake i teet ta ties te tenta 6 Blocked Exhaust csi A et en Uc HH edes 21 7 Flame Sensor Error Gas Control Valve Gas Control Valve Voltage Tests Flame Sensor Flame Sensing Operation Flame Sensing Current 25 semi ELLO 26 Powered Anod S etre ia dtes rie riae pedo 26 Power anode cleaning and 26 9 Anode Short d cerne rr eae tr et hein 28 10 Temperature Probe Short Upper
9. Ensure the water heater is properly grounded The water heater Control System requires an adequate earth ground for flame sensing verification see Flame Sensing Operation on Page 24 Inadequate grounding to the water heater and or the Burner will cause the Ignition Failure fault condition and Control System lock out See Electrical Connections section on Page 35 Servicing should only be performed by a Qualified Service Technician 37 OPERATION AND SERVICE HOW IT WORKS This section of the Service Handbook will cover operation common service procedures and water heater construction The water heater covered in this Service Handbook has a helical shaped coil heat exchanger that is submerged in the storage tank These water heaters use a top mounted down fired radial design Burner This is a forced draft burner hot burning gases are forced through the heat exchanger under pressure and exit through the exhaust vent connection located at the bottom of the water heater Starting at the top air and fuel gas are drawn in by the Combustion Blower and Venturi Flue gases and are forced through the helical shaped heat exchanger by the Combustion Blower and out through the exhaust vent outlet COMBUSTION BLOWER The Combustion Blower is an assembly that includes the blower housing blower motor and an electronic speed control The Combustion Blower is controlled by the CCB Central Control Board and is powered by a 3 pin wiring plug receiving 120
10. WHITE 600 AMP 32277 LOCKING 250 FORK CONNECTOR 6 PL 50 amp 00 ALL WIRES WIRE LENGTH MEASURED FROM END OF CONNECTOR TO PLANE WHERE WIRES ENTER DRIVE 4 CIRCUIT CONNECTOR AMP MALE QUICK CONNECT 1 480703 0 CAP 2 520103 2 3 PL WITH AMP 350551 1 Tl BLACK SOCKETS 1 4 STRIP ON 2 WHITE DRIVE END 13 RED 1 WHITE W GREEN 2 WHITE W BLACK 3 WHITE W YELLOW 4 wHie VFD Variable Frequency Drive Servicing should only be performed by a Qualified Service Technician 41 BURNER ASSEMBLY The Burner is a radial design burner with a steel fiber jacket on the outer surface and is part of a larger Burner Assembly Figures below show side views of the complete Burner Assembly removed from the water heater with key components identified See the exploded view of the Combustion Blower amp Burner Assembly section on Page 4 also SUF 60120 100250 Models SUF 119300 119500 Models 42 Servicing should only be performed by a Qualified Service Technician COMBUSTION BLOWER AND BURNER REMOVAL INSTALLATION INSTRUCTIONS Refer to the Combustion Blower amp Burner Assembly Heater Top View images in this Service Handbook and the Instruction Manual supplied with the heater for heater component locations COMBUSTION BLOWER BURNER REMOVAL 1 Turn the water heater s Enable Disable switch to the Disable Position Turn off the electrical circuit breaker that serves the water heater Close the Main Ga
11. Operate heater through at least one complete heating cycle to verify it is operating properly Servicing should only be performed by a Qualified Service Technician 43 SPARK IGNITER The water heaters covered in this Service Handbook use a Spark Igniter The Spark Igniter has two rods the sparking rod that has ceramic insulation and the grounding rod see Figure below During trial for ignition the Control System powers a high voltage transformer Ignition Control from J6 and the Ignition Control supplies high voltage to the sparking rod via the ignition cable The high voltage potential across the gap between the sparking rod and the grounding rod generate a spark Spark Igniter 1 8 Spark Gap Spark Igniter 5 16 Gap from meae Burner Flame Sensor 1 2 Gap from Burner SUF 60120 100250 Models 44 Servicing should only be performed by a Qualified Service Technician Spark Igniter 1 8 Spark Gap Spark Igniter 5 16 Gap from Burner Flame Sensor 13 16 Gap from Burner at the tip of Sensor Rod SUF 119300 119500 Models The Control System is programmed to start sparking a few seconds before the Gas Control Valve opens See the Sequence Of Operation Flow Chart on Page 6 Service Notes The animated lighting bolt Status Icon is visible on the UIM See UIM User Interface Module Screen Figure on Page 54 Ensure the wiring and connections between the J6 Socket on the CCB and the Burn
12. Table on next page The Control System interprets changes in the temperature sensor resistance as changes in water temperature and uses this data to activate and deactivate heating cycles and displays this temperature in the Control System menus see UIM User Interface Module Screen Figure on Page 54 The Control System constantly monitors the Temperature Sensor The Control System is programmed to declare a fault condition if the resistance of the temperature sensor drops below 390 ohms shorted or above 56 000 ohms open Servicing should only be performed by a Qualified Service Technician 29 If the resistance of the Temperature Sensor is below 390 ohms the Control System will lock out and display Temp Probe Short on the UIM If the resistance of the temperature sensor is above 56 000 ohms the Control System will lock out and display Temp Probe Open on the UIM The electrical circuit breaker that serves the water heater must be turned off and on again to reset the Control System Note the Control System will not reset unless the condition has been corrected TEMPERATURE SENSOR TEST 1 Turn off the circuit breaker that serves the water heater 2 Remove the top cover on the water heater 3 Disconnect the four pin plug socket connection from the Temperature Probe outside the CCB enclosure in the middle see Figures on next page Using an ohm meter set the ohm meter range to a scale just above 30 000 ohms 5 Check resistance be
13. lt 4 _ Operational buttons enter exit menus select menu items Operational buttons are multi functional Their current function is defined by activate adjustment modes the text that appears directly above each button on the LCD screen confirm cancel changes UIM User Interface Module Screen 54 Servicing should only be performed by a Qualified Service Technician COMMERCIAL GAS HIGH EFFICIENCY WATER HEATERS Visit the Information Central link of www statewaterheaters com for a listing of available Service Handbooks For additional information contact State Water Heaters 500 Tennessee Waltz Parkway Ashland City TN 37015 1 800 527 1953 www statewaterheaters com 2014 State Industries Inc 329298 000
14. J10 Lower Probe Blower Prover Inlet retum Prover power uet retur inlet power 1 Black Pressure Proerretum Tutiet power Aux 2 NO 5 Green J1 Aux T Common Field Box Aux TNO Aux TNC N HIGH Voltage Em reen 18AWG AWM wire 105 C 600V UL style 1015 Flame rod wire 200 C 300V UL 1180 e a oc cu T Red CCB J15 Pressure Switches White 4 Green Switch 2 Red Tite mm mm Black Anode uj i ondensal Connects burner Yellow Green Ground Bar U7 Display Display AIN mmm wm multi conductor power limited cable 18AWG 80 C 300V UL category QPTZ gt Spark ignition wire 220 C 25kVDC 8mm EMI suppression NIY edsa Er aoa Condensate Gas PS CCBJ14 Limit String PH wo White Orange Dgnd e pri P CCBJ12 W4 White Blue PLA WS WhiteBrown Green bolt pe Gas Pressure Switch 7 mmm Gas vahe Configuration E WI Greer SDA data 1 T T Wi Red
15. VAC from the Junction Box The CCB sends a signal from the J5 socket to a 5 pin wiring socket on the SUF 60120 100250 blower and on the SUF 119300 119500 top cover control assembly The signal is an electronic instruction to start stop and control blower speed The Combustion Blower runs at higher speeds during the Pre Post Purge operating states and runs ata lower speed during the Trial For Ignition operating state The Igniter Status icon is displayed on the UIM during the Trial For Ignition operating state MODULATION The water heaters covered by this Service Handbook are capable of modulating their firing rate The CCB monitors the water temperature in the tank and regulates the firing rate to achieve the target temperature setpoint The firing rate is dictated by the hot water draw proximity to the tank temperature setpoint and various other temperature limitations Periodically when the heater is in modulation mode the CCB will increase the blower speed for a short period of time to clear out any condensation that may have accumulated in the heat exchanger then decreases the blower speed back to the modulating firing rate required to maintain the desired tank temperature setpoint This ramping up and down of the blower speed is considered normal operation of the water heater 38 Servicing should only be performed by a Qualified Service Technician Service Note The 5 pin PWM signal plug MUST remain plugged in to the 5 pin
16. into pins 11 and 12 of the J14 Plug on the CCB during the Ignition Verification or Heating operating states see Figure below 24 VAC should be present Note that the Gas Control Valve Voltage is only present for a short period of time during the ignition period Check for 24 VDC at the plug end of the 24 Volt Gas Control Valve wiring harness during the Ignition Verification operating state Loosen the retaining screw for the 24 Volt Gas Control Valve wiring harness plug and disconnect the plug see Gas Control Valve on Page 22 Lay the plug end upside down on a flat surface Using an DC volt meter insert the two test probes into the two outside plug sockets see Figure below 24 VDC should be present AC VOLTAGE TEST DC VOLTAGE TEST Servicing should only be performed by a Qualified Service Technician 23 FLAME SENSOR Ignition of the Burner is controlled electronically The principle of operation for electronic ignition relies on flame sensing current to prove the fuel gas flowing to the Burner has been ignited Flame sensing requires an adequate earth ground to the water heater s Burner see Electrical Connections on Page 35 FLAME SENSING OPERATION The Flame Sensor is a metal conductor rod mounted in a ceramic insulator The Control System applies an AC voltage to the Flame Sensor through a single wire The burner flame will conduct a small amount of electrical current The burner must be properly grounded for current t
17. it applies to servicing the water heater This Service Handbook does not replace or supersede the Instruction Manual that came with the water heater Always refer to the Instruction Manual for complete installation instructions If the Instruction Manual is not on hand copies can be obtained from the manufacturers web site or by calling the technical support phone number shown on the back cover of this Service Handbook CLOSED WATER SYSTEMS Water supply systems may because of code requirements or such conditions as high line pressure among others have installed devices such as pressure reducing valves check valves and back flow preventers Devices such as these cause the water system to be a closed system THERMAL EXPANSION As water is heated it expands thermal expansion In a closed system the volume of water will grow when it is heated As the volume of water grows there will be a corresponding increase in water pressure due to thermal expansion Thermal expansion can cause premature tank failure leakage This type of failure is not covered under the limited warranty Thermal expansion can also cause intermittent Temperature Pressure Relief Valve operation water discharged from the valve due to excessive pressure build up This condition is not covered under the limited warranty The Temperature Pressure Relief Valve is not intended for the constant relief of thermal expansion Aproperly sized thermal expansion tank must be installed
18. method shown in Figure below Enable water heating and ensure a call for heat is active when the Control System energizes the 24 Volt Gas Control Valve the meter will measure flame sensing current during normal operation Service Notes The most common cause of Ignition Failure lock out is a worn Flame Sensor The Flame Sensor should be inspected and cleaned anytime the measured flame sensing current is below 8 pA or the Burner has been removed Clean the Flame Sensor with ultra fine steel wool DO NOT use a coarse abrasive material such as sand paper Inspect the ceramic insulator on the Flame Sensor for cracks replace the Flame Sensor if it is damaged An open flame sensing circuit caused by disconnected or loose connectors can also cause ignition failure Check all wiring and wiring connections between the Flame Sensor and the J14 connector on CCB circuit board see CCB Circuit Board Layout on Page 25 The Burner not being grounded will cause Ignition Failure see Electrical Connections on Page 35 Ensure the water heater and the Burner are properly grounded Servicing should only be performed by a Qualified Service Technician 25 8 NO WATER CAUSES No Water The controller has not detected a voltage potential Alert occurred 2 mins ago of water in the tan k No water detected by Powered No water or low water in tank Anode Loose or open wiring connections to Power Anode s Call a service professiona
19. modulating their input rate Therefore the RPM readings can be in between the Heating Speed and Minimum Modulation Speed RPMs The input rate should be verified with the water heater operating at full input rate Heating Heating Minimum Minimum Ignition Ignition Speed Speed Modulation Modulation Speed Speed RPM VFD Hertz RPM VFD Hertz RPM VFD Hertz Reading Reading Reading SUF 119300 Nat 3450 117 4 2350 4500 153 8 SUF 119300 LP 3200 108 8 2310 5770 198 2 SUF 119400 Nat 4625 158 3 2350 4500 153 8 SUF 119400 LP 4200 143 2 2310 5770 198 2 SUF 119500 Nat 5750 198 2 2350 4500 153 8 SUF 119500 LP 5225 179 8 2310 5770 198 2 40 Servicing should only be performed by a Qualified Service Technician VARIABLE FREQUENCY DRIVE SUF 119300 THRU 119500 The SUF 119300 119500 models have a variable frequency drive VFD that controls the rpm of the blower motor The VFD receives a signal from the central control board that instructs the VFD to transmit the proper frequency to the blower to produce the proper blower speed and proper input Three conditions must be met for the frequency drive to start the blower 1 120VAC must be supplied to the VFD 120VAC input 2 The ignition control board closes an enable circuit terminals LI1 and 24V 3 The ignition control board sends a 1 10VDC instruction terminals OV and AI1 VFD Display 3 CIRCUIT CONNECTOR AMP 1 480701 0 CAP WITH AMP 350547 PINS 1 BLACK 2 GREEN 3
20. or 29 arret terret np 29 Temperature Sensor Test ECO Continuity Test 11 Temperature Probe Open Upper or Lower VENTINQG ee credet i v e it eere ike to Ere E EU Deep 33 General Venting Information sees 33 INTAKE AIR CONNECTION ic treu o nhe 34 ELECTRICAL CONNECTIONS ALL MODELS eee 35 Electrical Wiring eter sii n canas eer hint tion a raten paie 35 Power Supply Conriections nc cri rr ceteri ion terrenae 35 Enable Disable Switch ire tti te cibi eti roten arti Pes 36 Power Supply Test ese aoc eec Mane viia INSTALLATION CHECK LIST OPERATION AND SERVICE HOW IT WOIKS nit c eee rector ERES Aen 38 COMBUSTOR BIOWEB 38 MoOQulaltiQli icri Leer ast ceret eem 38 BLOWER SPEED CONTROL SUF 119300 THRU 119500 40 VARIABLE FREQUENCY DRIVE SUF 119300 THRU 119500 41 B RNER ASSEMBLY 5 rc ener EC EH A CY CEN RE EHE 42 COMBUSTION BLOWER AND BURNER REMOVAL INSTALLATION INSTRUGTIONS 5 rtr re ew ee RR EE PERPE YET Rd 43 SPARKIGNITE R c 44 GAS ORIFICE SUF 119300 THRU 119500 MODELS 46 Orifice Chart SUF 119300 thru 119500 46 CCB CENTRAL CONTROL
21. pressure switches A sign before the pressure indicates a positive pressure above atmospheric pressure A sign before the pressure indicates a negative pressure in a vacuum below atmospheric pressure Tolerances are specified to allow reasonable leeway for imperfections and inherent variability without compromising performance PRESSURE SWITCH SETTINGS Blower Prover Blocked Air Blocked Exhaust Low gas 0 04 WC Nat 0 05 WC Intake 0 05 WC 0 05 WC LP 0 05 WC SUF 60120 0 75 W C 2 50 W C 2 00 W C 4 4 W C Nat 8 5 W C LP SUF 100150 100250 1 00 W C 2 50 W C 2 00 W C 4 4 W C Nat 8 5 W C LP SUF 119300 119500 1 00 W C 2 30 W C 2 00 W C 4 8 W C Nat 8 5 W C LP Pressure Test 1 Turn off the circuit breaker that serves the water heater 2 Disconnect the sensing tube from the switch being tested and add a 3 16 tee to the sensing tube Add a short piece of sensing tube connecting the tee and the pressure switch being tested w Connect a digital manometer to the open side of the tee with another piece of sensing tube gt Restore power to the water heater if the water heater does not begin a heating cycle raise the Operating Set Point to activate a heating cycle When the Combustion Blower comes on and ramps up to full speed record the pressure reading Repeat this test for all three pressure switches as necessary Compare the pressure readings taken to the activa
22. to confirm proper operation If flame is not present cycle the unit Off by turning the Enable Disable switch to Disable wait for 5 seconds and cycle the unit On by turning the Enable Disable switch to Enable to see if the error clears See Flame Sensor section on Page 24 thru Page 25 GAS CONTROL VALVE The 24 Volt Gas Control Valve on these water heaters is DC voltage valve The CCB sends 24 VAC to the valve and the AC voltage is rectified into a DC voltage by electronics contained inside the plug end of the 24 Volt Gas Control valve wiring harness see Figures below 24 VAC SOLENOID amp WIRE HARNESS GAS CONTROL SUPPLY GAS CONNECTION PRESSURE SWITCH COMBUSTION AIR INLET GAS CONTROL VALVE ASSEMBLY SUF 60120 100250 MODELS 22 Servicing should only be performed by a Qualified Service Technician SUPPLY GAS CONNECTION LOW GAS PRESSURE SWITCH 24 VAC SOLENOID amp WIRE HARNESS GAS CONTROL VALVE ASSEMBLY SUF 119300 119500 MODELS GAS CONTROL VALVE VOLTAGE TESTS 1 The animated Gas Control Valve Status Icon is displayed the Control System UIM during these operating states See UIM User Interface Module Screen Figure on Page 54 Check for 24 VAC supplied to the 24 Volt Gas Control Valve at pins 11 and 12 of the J14 Plug on the CCB see CCB Cover Removal And Replacement on Page 48 and CCB Circuit Board Layout on Page 49 Using an AC volt meter insert the two test probes
23. Air Intake fault conditions AIR INTAKE SCREEN AIR INTAKE SCREEN remove for Direct Vent remove for Direct Vent 3 INCH INTAKE AIR CONNECTION FACTORY INSTALLED dix REDUCER COUPLING FACTORY INSTALLED ASE AIRCONNECTION INTAKE AIR CONNECTION DETAIL SUF 60120 100250 Models SUF 119300 119500 Models AIR INTAKE SCREEN Service Notes 34 Plastic debris left on the edges of intake air pipe sections after cutting must be removed on Direct Vent installations This debris can collect inside and clog the Burner which can cause poor combustion sooting rough starting rough operation and Ignition Failure fault conditions and Control System lock outs The Burner is a radial design that can trap debris see Combustion Blower amp Burner Assembly section on Page 4 Exceeding the equivalent length limitations for the vent piping will cause Blocked Exhaust fault conditions and Control System lock outs Exceeding the equivalent length limitations for the intake air piping will cause Blocked Air Intake fault conditions and Control System lock outs Exceeding the maximum number of elbows allowed for the intake air and or vent piping will also cause Blocked Air Intake and Blocked Exhaust fault conditions and Control System lock outs Using smaller intake air and or vent pipe than required for the installed equivalent length will also cause Blocked Air Intake and Blocked Exhaust fault conditions and Control System lock outs Ser
24. F 119300 119500 Models Servicing should only be performed by a Qualified Service Technician 9 T 8 Record the supply gas pressure Use the Enable Disable Switch located on the front of the water heater and put the unit in enabled mode The settings on the water heater may need to be changed to cause the water heater to operate Note the Operating Temperature Set Point so that the unit can be returned to this setting at the conclusion of this test procedure Increase the Operating Set Point if necessary to cause the water heater to have a call for heat Record the supply gas pressure when the Ignition Activation operating state begins when the animated Gas Control valve Status Icon appears on the UIM Screen The supply gas pressure will typically drop as the Gas Control Valve opens Putting The Water Heater Back In Service 10 11 12 13 14 19 16 Lower the Operating Set Point to end the heating cycle Use the Enable Disable Switch located on the front of the water heater and put the unit in disabled mode Close the main gas shutoff valve serving the water heater Disconnect manometer sensing tube Close the Supply Gas Pressure Test Port on the Gas Control Valve Turn the needle valve slotted head clockwise until tight Open the main gas shutoff valve serving the water heater and check for leaks at the Gas Control Valve test ports Use the Enable Disable Switch located on the front of the water heater and p
25. N This test will be performed while the Combustion Blower is running at high speed during the Pre Purge operating state This test is necessary when a pressure switch has passed the Continuity Test During Standby shown on Page 12 but has failed the Continuity Test During Operation above to determine if the pressure switch is defective or not This test requires a digital manometer see Tools Recommended on Page 2 Service Notes Before performing this test examine the sensing tube connections on the water heater s sensing ports and on the pressure switch Check for wear cracks leaks kinks or any kind of debris or condensate in the sensing tubes repair replace as necessary To determine if a pressure switch is operating properly you must first know the switch action whether the switch activates on a rise or a fall in pressure and the activation pressure the switch will activate at Activation pressures are provided in Pressure Switch Settings Table on Page 14 Switch actions are as follows Servicing should only be performed by a Qualified Service Technician 13 Blower Prover Switch normally open contacts close on a rise in pressure Blocked Air Intake Switch normally closed contacts open on a fall in pressure Blocked Exhaust Switch normally closed contacts open on a rise in pressure Activation Pressures Pressure Switch Settings Table below shows the activation pressures and tolerance for each of the three
26. NFPA 70 or the Canadian Electrical Code CSA C22 1 and local requirements When installed the water heater must be electrically grounded in accordance with local codes or in the absence of local codes with the National Electrical Code ANSI NFPA 70 or the Canadian Electrical Code CSA C22 1 If any of the original wire as supplied on the water heater must be replaced it must be replaced with UL Listed Power Limited Circuit Cable of the same size and rating as original wiring POWER SUPPLY CONNECTIONS The 120 VAC black hot wire from the power supply must connect to the black lead wire or the L1 terminal block location in the junction box and the 120 VAC white neutral wire must connect to the white lead wire or the Neutral terminal block location in the junction box for correct polarity See Junction Box Assembly Figure on next page Power supply connections must be made as follows 1 Turn off the electrical circuit breaker that serves the water heater 2 Remove the junction box cover 3 Connect the 120 VAC black hot wire from the power supply to the black lead wire or the terminal block location marked L1 inside of the junction box located on top of the water heater If the black lead wire is used make the connection inside of the junction box with a properly sized wire nut See Junction Box Assembly Figure on next page and Wiring Diagrams on Page 52 and Page 53 Note If electrical connection is made directly to termi
27. See Fault And Warning Codes beginning on Page 7 for service procedures relating to the fault conditions mentioned below 1 10 dus The vent exhaust pipe must not be combined or connected to any other appliance s vent system or chimney The intake air pipe must not be combined or connected to any other appliance s intake air piping The water heaters covered in this Service Handbook are condensing appliances Condensate will form in the vent pipe during normal operation condensate can also form in the intake air piping in certain circumstances Ensure the intake air and or vent piping is not installed in a manner that will allow water to be trapped in the piping Install a condensate tee in the intake air and or vent piping Condensate trapped in the intake air and or vent piping will lead to Blocked Exhaust and or Blocked Air Intake fault conditions and Control System lock outs Ensure the intake air and or vent piping is the correct size for the installed length See the venting requirements section in the Instruction Manual that came with the water heater Using smaller pipe than is required will lead to Blocked Exhaust and or Blocked Air Intake fault conditions and Control System lock outs Ensure the intake air and or vent piping are within the maximum equivalent lengths required in the Instruction Manual that came with the water heater Exceeding the maximum length or number of elbows allowed will also lead to Blocked Exhaust an
28. Service Handbook COMMERCIAL GAS HIGH EFFICIENCY WATER HEATERS FOR MODELS State SUF 60120 THRU SUF 100250 WATER HEATERS SUF 119300 THRU SUF 119500 500 Tennessee Waltz Parkway SERIES 200 201 Ashland City TN 37019 INSTALLATION CONSIDERATIONS PRE SERVICE CHECKS CONSTRUCTION OPERATION amp SERVICE TROUBLESHOOTING SERVICING SHOULD ONLY BE PERFORMED BY A QUALIFIED SERVICE TECHNICIAN 329298 000 PRINTED IN THE U S A 0914 TABLE OF CONTENTS INTTRODUCGTION 5 rrr veteri ae a erar eee een vere e iA 2 Qualifications i cerro enne 2 Service Warning Service Reminder 5 rtc tv eae De iu 2 INSTALLATION CONSIDERATIONS seen 3 Instruction Manual ssssssseseeeeeeeeneenem eene nnne 3 Closed Water Systems aciei ig 3 Thermal Expansion coti ente eL D Deere cosa ses Deeds 3 Air Requirements ie ier GRE a B eU iac eee 3 Contaminated Af DNE Rm 3 FEATURES AND COMPONENTS riti eanna 4 Combustion Blower amp Burner 4 Top View SUF 60120 100250 5 Top View SUF 119300 119500 Models SEQUENCE OF OPERATION FLOW 6 FAULT AND WARNING CODES erre tt ctr eate epu 7 1 Low
29. able and fall within the requirements stated on the water heater rating plate Readings should be taken with all gas burning equipment off static pressure and with all gas burning equipment running at maximum rate dynamic pressure The gas pressure supplied to this unit must be below the maximum and above the minimum pressures listed on the unit s rating plate and must not drop more than 1 5 W C when unit is operating at the high fire rate along with all additional gas appliances operating on the same gas supply system Pressure drops that exceed 1 5 W C may cause rough starting noisy combustion or nuisance outages Increases or spikes in static pressure during off cycles may cause failure to ignite or in severe cases damage to appliance Gas Control Valves If your low pressure system does NOT meet these requirements do not operate this unit The installer is responsible for ensuring that the gas supply pressures meet the requirements described above and listed in the table Failure of the gas supply to meet these requirements is not covered under the warranty High Pressure building supply systems use pressures that exceed 14 W C 1 2 PSI Gauge These systems must use field supplied regulators to lower the gas pressure to less than 14 W C 1 2 PSI Gauge Water heaters require gas regulators that are properly sized for the water heater s BTU input and capable of delivering the rating plate specified pressures Gas supply systems where pre
30. ardous and cause product failure If the water heater is installed in beauty shops barber shops or laundries with dry cleaning equipment it is imperative the water heater be installed in a Direct Vent configuration so that air for combustion is derived directly from the outdoor atmosphere through a sealed intake air pipe See the venting installation section in the Instruction Manual that came with the water heater for more information on Direct Vent installations Servicing should only be performed by a Qualified Service Technician 3 FEATURES AND COMPONENTS COMBUSTION BLOWER amp BURNER ASSEMBLY Low Gas Pressure Switch Combustion Blower Gas gon rol Air Intake Assembly Blower Gasket Spark Igniter Ground Wire Flame Sensor paste Spark Igniter T Spark Igniter Gasket iz Blower Adapter U ME po cte Gasket Ignition Cable lt Burner Sight Glass ese ht Glass Gasket Burner Plate Burner Plate Gasket 150 250 Models Only SS Heat Shield 150 250 Models Only SS gt Flue Ring Gasket Sc SUF 60120 100250 Models Ignition Cable Spark Igniter di Air Intake Assembly Flame Sensor Spark Igniter Gasket N Combustion Blower pa 2 5 Sight Glass Venturi Sight Glass Gasket a Burner Plate Gasket i L SS Heat lt a SUF 119300 119500 Models 4 Servicing should only be performed by a Qualified Service Technician
31. d or Blocked Air Intake fault conditions and Control System lock outs The metal condensate elbow supplied with the water heater has a built in water trap thus it is not necessary to form another water trap Condensate drain blockage will cause the exhaust elbow to fill with water and lead to Blocked Exhaust fault conditions and Control System lock outs Ensure the vent and intake air terminations have adequate clearances from each other and the terminations of other appliances Failure to maintain adequate clearances can cause the recirculation of flue gases between the vent and intake air piping Recirculation of flue gases will cause poor combustion sooting ignition failure rough starts rough operation premature failure of the heat exchanger and icing of the combustion air intake during severe cold weather Direct vent terminations being installed in dead air spaces such as alleys atriums and inside corners can also cause the recirculation of flue gases between the vent and intake air piping To prevent the recirculation of flue gases maintain as much distance as possible between the intake air and vent terminations Ensure the screens in the factory supplied terminations are securely installed to prevent blockage in the intake air and or vent piping On Direct Vent installations ensure the screen at the intake air connection on the water heater was removed before the intake air piping was connected see Intake Air Connection on Page 34
32. during a heating cycle the Control System will immediately de energize the 24 Volt Gas Control Valve After 3 failed trials for ignition the Control System will lock out and display Ignition Failure fault condition on the UIM If flame sensing current drops below 1 0 pA during a heating cycle the Control System will de energize the 24 Volt Gas Control Valve and enter the Inter Purge operating state After the Inter Purge operating state the Control System will try for ignition again if a call for heat is still active see the Sequence Of Operation Flow Chart on Page 6 24 Servicing should only be performed by a Qualified Service Technician FLAME SENSING CURRENT TEST During the heating cycle the flame sensing current is normally greater than 8 0 uA with a clean Flame Sensor Over time the Flame Sensor can degrade and this will reduce flame sensing current With heavier use more heating cycles greater load this will occur more quickly Measuring flame sensing current requires a test meter with DC micro amp function see Tools Recommended on Page 2 The meter s selector is set to DC micro amps The two test leads from the meter are placed in series with the flame sensing circuit This can be done at the spade male female flame sensing wiring connectors See Figure below To measure flame current disable water heating by turning off the Enable Disable Switch located in the front of the water heater and connect the test meter following the
33. em lock outs occur after the CCB enclosure cover has been removed and replaced remove the cover again to ensure none of the wiring connectors are unplugged and or any of the wiring has been pinched cut or damaged Unlike previous water heaters in this product line the individual control boards inside the plastic enclosure are serviceable parts See the Parts List that was shipped with the water heater for the appropriate part numbers for each component 48 Servicing should only be performed by a Qualified Service Technician CCB CIRCUIT BOARD LAYOUT eo ol joool gH SIF Z ani CENTRAL CONTROL BOARD 4i 2 3 5000 POWER BOARD ASSEMBLY 49 Servicing should only be performed by a Qualified Service Technician CCB CONNECTION IDENTIFICATION J1 Socket High Voltage In BESRPRON 6 Nem J5 Socket Blower Logic VFD Blower ewe BEScRPHON O J6 Socket 120V Out PN amp BESCRPHON 3 4 Line Voltage Out J9 Socket Temperature Probe PN _ BESGRPHON J12 Socket Configuration Key J13 Socket Display AIN 50 Servicing should only be performed by a Qualified Service Technician J14 Socket Limit String PN amp __ BEScRPTON
34. ength and maximum number of elbows Check actual pipe pressure with a manometer during blower operation See Pressure Switch Tests section on Page 12 thru Page 15 under Blower Operation Error on Page 11 20 Servicing should only be performed by a Qualified Service Technician 6 BLOCKED EXHAUST CAUSES Blocked Exhaust The Blocked Exhaust Switch has detected a possible restriction the exhaust pipe Restriction in exhaust pipe Check exhaust pipe and termination for blockage Call a service professional Your Company Name Here press DOWN for more BACK ADVANCED CHECK REPAIR Check pipe for restriction or excessive equivalent length See Instruction Manual for pipe size length and maximum number of elbows Check actual pipe pressure with a manometer during blower operation See Pressure Switch Tests section on Page 12 thru Page 15 under Blower Operation Error on Page 11 Servicing should only be performed by a Qualified Service Technician 21 7 FLAME SENSOR ERROR CAUSES Flame Sensor error The Flame Sensor has detected flame when the M UH RE Gas Control Valve is supposed to be off Flame Sensor rod detected flame when gas valve should be off Shut off gas until repaired Press the Advanced button for press DOWN for more BACK ADVANCED CHECK REPAIR Look through sight glass If flame is present shut the main gas supply off See Gas Control Valve section below
35. ent configurations derive all combustion air directly from the outdoor atmosphere through a sealed intake air pipe and discharge all flue gases to the outdoor atmosphere through a sealed vent exhaust pipe Direct Vent configurations have two pipes connected to the water heater one vent pipe and one intake air pipe Direct Vent configurations can also be terminated in a vertical or horizontal arrangement PIPE SIZE REQUIREMENTS Ensure the correct size pipe has been used for the length of intake air and or vent piping installed Refer to the Instruction Manual supplied with the water heater for the correct size and length of vent piping Servicing should only be performed by a Qualified Service Technician 33 INTAKE AIR CONNECTION The intake air connection has a screen and a hose barb installed at the factory see Figure below The intake air connection screen is installed to prevent debris from entering the Combustion Blower and or Burner This screen is left in place when the water heater is installed in a Power Vent configuration but must be removed before connecting the intake air piping on Direct Vent installations Once the intake air pipe is installed the screen if not removed would be hidden from view and may become clogged with debris over time This can cause poor combustion and Blocked Air Intake fault conditions and Control System lock outs Ensure this screen has been removed on all Direct Vent installations if experiencing Blocked
36. er Adapter are not broken pinched or disconnected Ensure there is approximately 120 VAC at the J6 Socket on the CCB tis a good practice to check for any crack or damage to the ceramic insulator If any crack is found replace the Spark Igniter Do not contaminate the ceramic insulator as this could make a shortage pass between the spark rod and grounding rod Ensure good connection between the ignition cable and Spark Igniter Servicing should only be performed by a Qualified Service Technician 45 GAS ORIFICE SUF 119300 THRU 119500 MODELS Refer to Orifice Chart below for correct gas orifice size SUF 60120 thru 100250 Models and all Natural gas models do not use a gas orifice Without Orifice w LP Gas Orifice Gas Control Without Orifice Natural Gas Gas Control With Orifice Propane LP SUF 119300 119500 Models ORIFICE CHART SUF 119300 THRU 119500 MODELS Bel 119300 119400 119500 Natural N A N A Propane LP 0 344 0 344 46 Servicing should only be performed by a Qualified Service Technician CCB CENTRAL CONTROL BOARD The CCB is a printed circuit board mounted inside a protective plastic enclosure see Figures below and on next page The CCB circuit board is the main control All instructions for ignition and temperature control originate from this circuit board Diagnostic and operational messages are generated by the CCB and sent to the UIM see UIM User Interface Module Screen on Page 54
37. g taken at the Blocked Air Intake Switch sensing tube does not reach or drop lower than the pressure shown in the above Table AND the switch contacts were opening during the Continuity Test During Operation shown on Page 13 the switch is defective and must be replaced If the pressure reading taken reaches or drops lower than the pressure shown in the Pressure Switch Settings Table on Page 14 and the switch contacts were opening during the Continuity Test During Operation shown on Page 13 the switch IS NOT defective and should not be replaced Check for restrictions at the intake air connection on the water heater check for too small of pipe installed too many equivalent feet and or too many elbows in the intake air piping Check for low points in the intake air piping where water may be collecting and blocking the intake air piping Check for any restrictions or debris at the intake air termination outdoors Check for condensate water in the sensing tube switch if the sensing tube has water in it replace the Blocked Air Intake Switch and the tube Ensure the sensing port is oriented properly see Intake Air Connection on Page 34 Blocked Exhaust If the pressure reading taken at the Blocked Exhaust switch sensing tube does not reach or rise above the activation pressure given in the above Table AND the switch contacts were opening during the Continuity Test During Operation on Page 13 the switch is defective and must be replaced If the p
38. ge cycle Control System Locks Out Blower Prover Open Fault Msg is displayed Blower Prover switch contacts confirmed closed by control system Spark Ignition Control is energized 24 Volt Gas Valve is energized gas flows to Main Burner Is flame sensed at the Main Burner control system monitors the flame sensor Water is heated to 24 Volt Gas Valve set point de energized 24 Volt Gas Valve de energized Inter Purge cycle Retries up to two more times Post Purge cycle Control System Locks Out Ignition Failure Fault Msg is displayed Water heater goes into standby mode 6 Servicing should only be performed by a Qualified Service Technician FAULT AND WARNING CODES 1 LOW GAS PRESSURE CAUSES The Low Gas Pressure Switch is detecting gas pressure below the value required for proper Low Gas Pressure Fault occurred 2 mins ago Gas pressure is below minimum required to operate this unit Check operation gas pressure and switch Call a service professional Your Company Name Here press DOWN for more BACK ADVANCED CHECK REPAIR Check Low Gas Pressure Switch wiring and connectors Connectors must be clean and tight Determine proper minimum pressure from rating plate Use manometer or gauge to check gas pressure during all stages of operation with all other appliances firing f pressure falls below rating plate requirement supply pipe may be too small f
39. h removes electrical power from the Gas Control Valve so that water heating is disabled The display CCB and other electrical components will still be energized and the display will read Water Heating Disabled The Enable Disable Switch can be used to disable operation and reset error codes To operate the water heater make sure the switch is set to Enabled position Turn power off at the source circuit breaker during installation and servicing POWER SUPPLY TEST Proper grounding and polarity can be verified with an AC volt meter by taking three voltage readings at the power supply wiring inside the water heater s 120 VAC junction box Check for AC voltage between 1 Hot amp Neutral should be approximately 120 VAC 2 Hot amp Ground should be approximately 120 VAC 3 Neutral amp Ground should be approximately 0 VAC 36 Servicing should only be performed by a Qualified Service Technician INSTALLATION CHECK LIST The list below represents some of the most critical installation requirements that when overlooked often result in operational problems down time and needless parts replacement Before performing any troubleshooting procedures use the list below to check for installation errors Costs to correct installation errors are not covered under the limited warranty Ensure all installation requirements and instructions contained in the Instruction Manual that came with the water heater have been observed and followed
40. he two wires to each pressure switch for this test 1 If the water heater is in a heating cycle lower the Operating Set Point to end the cycle 2 Turn off the circuit breaker that serves the water heater 3 Disconnect both wires at each pressure switch 4 Using an ohm meter set for continuity testing check for continuity between the two wiring terminals at each pressure switch see Figure below 5 After completing the tests confirm that all of the pressure switch wires are reconnected including the replacement part if necessary based on the Results Actions listed below Restore the electrical power to the water heater Reset the Operating Temperature Set Point if it was adjusted Run the water heater through a complete heating cycle before leaving to ensure it is operating properly Results Actions Passed Results If the Blower Prover switch contacts are open during this test infinite ohms open circuit the Blower Prover switch has passed the test If the Blocked Air Intake Switch and Blocked Exhaust Switch contacts are closed during this test zero ohms direct short these switches have passed the test Failed Results If the Blower Prover switch contacts are closed zero ohms direct short beep during this test the Blower Prover switch must be replaced If the Blocked Air Intake Switch and or Blocked Exhaust switch contacts are open during this test the switch s must be replaced Proceed to the Continuity Test During Operation on
41. ine is sized in accordance with the current edition of National Fuel Gas Code ANSI Z223 1 NFPA 54 or the Natural Gas and Propane Installation Code CAN CSA B149 1 GAS PRESSURE TEST 1 2 3 Use the Enable Disable Switch located on the front of the water heater and put the unit in disabled mode Turn off the supply gas to the water heater at the main gas shutoff valve serving the water heater Open the Supply Gas Pressure Test Port on the Gas Control Valve see Figures below Turn the needle valve slotted head 1 2 to 1 full turn counter clockwise with a small slotted screwdriver to open the valve A digital manometer see Tools Recommended on Page 2 is needed to check supply gas pressure To monitor supply gas pressure attach a sensing tube from Gas Control Valve Supply Gas Pressure Test Port to one digital manometer Open the main gas shutoff valve serving the water heater The manometer connected to the Supply Gas Pressure Test Port should read the static gas is not flowing supply gas pressure MANIFOLD GAS SUPPLY GAS AIR INTAKE PRESSURE PRESSURE PRESSURE REFERENCE CONNECTION TEST PORT TEST PORT N GAS CONTROL VALVE sie COMBUSTION 9 BLOWER CONNECTION U b COMBUSTION AIR INLET lt VENTURI MANIFOLD GAS SUPPLY GAS PRESSURE PRESSURE TEST PORT TEST PORT SUF 60120 100250 Models SU
42. ir or servicing of appliances and equipment that is experienced in such work that is familiar with all precautions required and that has complied with all the requirements of the authority having jurisdiction SERVICE WARNING If you are not qualified as defined by ANSI above and licensed or certified as required by the authority having jurisdiction to perform a given task do not attempt to perform any of the procedures described in this service handbook If you do not understand the instructions given in this service handbook do not attempt to perform any procedures outlined in this service handbook SERVICE REMINDER When performing any troubleshooting step outlined in this service handbook always consider the wiring and connectors between components Perform a close visual inspection of all wiring and connectors to and from a given component before replacement Ensure wires were stripped before being crimped in a wire connector ensure wires are crimped tightly in their connectors ensure connection pins in sockets and plugs are not damaged or worn ensure plugs and sockets are mating properly and providing good contact Failure to perform this critical step or failing to perform this step thoroughly often results in needless down time unnecessary parts replacement and customer dissatisfaction TOOLS RECOMMENDED Instruction Manual that came with the water heater All tools common to installation and service of commercial water heaters s
43. ise See Pressure Switch Tests section on Page 12 thru Page 15 under Blower Operation Error on Page 11 16 Servicing should only be performed by a Qualified Service Technician 4 IGNITION FAILURE CAUSES Onan Ignition Failure error either the burner is Flame not detected Clean flame rod a not igniting or the burner is igniting but the Flame Check gas supply Sensor is not detecting ignition flame Ignition Failure Fault occurred 2 mins ago Call a service professional Your Company Name Here press DOWN for more BACK ADVANCED CHECK REPAIR Determine whether or not the burner is igniting by looking through sight glass Because the control system will shut off the Gas Control Valve if 2 3 seconds if ignition is not detected you must look in the sight glass at the exact moment the Gas Control Valve icon appears on the display screen TESTING FOR IGNITION FLAME Set the Set Point Temperature high enough so there is a call for heat Recycle the unit off and back on by turning the Enable Disable switch to Disable for one second and then back to Enable The unit will begin an ignition cycle When the Gas Control Valve icon appears on display screen immediately look through the sight glass for a brief blue flame if you are getting an Ignition Failure error the flame if the burner ignites will only be present for 2 3 seconds BURNER IGNITES BRIEFLY If the burner ignites briefly
44. l Power Anode shorted to ground at wire connection Your Company Name Here press DOWN for more BACK ADVANCED See Powered Anodes section shown below CHECK REPAIR POWERED ANODES The water heaters covered by this Service Handbook are equipped with powered anodes SUF 60120 models only use 1 powered anode all others will have two These anodes do not need to be replaced unless damaged The CCB monitors the current through the anodes and will declare a fault if there is a disconnected wire or if there is no water in the tank Powered Anode Connections POWER ANODE CLEANING AND REMOVAL 1 Shut off gas water and power supply going to the heater 2 Relieve water pressure by either opening Temperature pressure relief valve T amp P relief valve if it is piped to a drain or drain some water off by connecting a hose to the drain valve 26 Servicing should only be performed by a Qualified Service Technician CLEANING METHOD If corrosion is present on the air side of the anode use a wire brush to clean the outer nut and brass wire terminal tab To clean the inner nut remove the outer nut and the brass wire terminal tab DO NOT REMOVE inner nut Clean with wire brush Reassemble and connect blue wire to brass terminal tab FRONT ANODE REPLACEMENT METHOD 1 2 3 Remove blue wire from anode brass terminal Using a 1 1 16 socket remove the anode Use a round wire brush to clean the spud threads If re
45. llow these steps Remove and reinsert the Gas Control Valve electrical connector Make sure the electrical connections pins are clean and that the connector fits tightly 24 VAC SOLENOID amp WIRE HARNESS SUPPLY GAS CONNECTION PRESSURE SWITCH COMBUSTION AIR INLET GAS CONTROL VALVE ASSEMBLY SUF 60120 100250 MODELS SUPPLY GAS CONNECTION LOW GAS PRESSURE SWITCH 24 VAC SOLENOID amp WIRE HARNESS GAS CONTROL VALVE ASSEMBLY SUF 119300 119500 MODELS 18 Servicing should only be performed by a Qualified Service Technician Remove and reinsert the circuit board end of the Gas Control Valve connector Make sure it is connected tightly and that the pins are clean Recycle unit again to start another ignition cycle If you still do not see a brief blue flame through the sight glass at the moment the Gas Control Valve icon appears on the display verify that 24 VDC is present on the connector pins 1 and 5 Use care to not bend or damage the pins while testing Connect test leads to the Gas Control Valve connector s pins Gently connect probes to Gas Control Valve connector s two outer pins Set the meter to DC volts X113 Recycle unit again to start an ignition cycle At the moment the Gas Control Valve icon appears on the display you should see 24 VDC on your meter This electrical signal will only last for 2 3 seconds if the burner does not ignite or the flame sensor does no
46. mum allowable gas supply pressure for the water heaters covered in this Service Handbook is 14 0 inches W C 3 49 kPa for natural and propane gas Install a positive lock up gas pressure regulator in the gas supply line if inlet gas pressure can exceed these pressures at any time Regulators must be sized to equal or exceed the BTU input requirements of the heater model and installed used and maintained according to manufacturer s specifications If a positive lock up regulator is installed follow these instructions 1 Positive lock up gas pressure regulators must be rated at or above the input Btu hr rating of all the gas appliances that are on the same system as the water heater 2 Supply gas regulators shall have inlet and outlet connections not less than the minimum supply gas line size for the water heater they supply 3 Refer to the gas pressure regulator s manufacturers installation instructions to determine its installation location requirements 4 After installing the positive lock up gas pressure regulator s an initial nominal supply pressure setting of 7 0 W C 1 74 kPA for Natural Gas and 11 0 W C 2 74 kPA for Propane LP while the water heater is operating is recommended and will generally provide good water heater operation Adjustments to the regulator maybe required to maintain a steady gas supply pressure 8 Servicing should only be performed by a Qualified Service Technician 5 When installing multiple water heate
47. nal block remove black lead wire before making connection 4 Connect the 120 VAC white neutral wire from the power supply to the white lead wire or the terminal block location marked Neutral inside of the junction box located on top of the water heater If the white lead wire is used make the connection inside of the junction box with a properly sized wire nut See Junction Box Assembly Figure on next Page and Wiring Diagrams on Page 52 amp Page 53 Note If electrical connection is made directly to terminal block remove white lead wire before making connection Servicing should only be performed by a Qualified Service Technician 35 5 Connect the ground wire from the power supply to the grounding lug inside the junction box See Junction Box Assembly Figure below and Wiring Diagrams on Page 52 amp Page 53 6 Replace junction box cover when connections are complete Note Do not apply power to the water heater before installation is complete and the water heater is filled with water Heater Wiring Factory Installed Ground L1 Black Wire Neutral White Wire Junction Box Assembly ENABLE DISABLE SWITCH WARNING POWER REMAINS ON WHEN UNIT IS DISABLED DISCONNECT POWER BEFORE SERVICING DISABLED mE ENABLED Enable Disable Switch The Enable Disable Switch is NOT an on off switch and does not disconnect 120 volt power to the CCB and other heater components When in the Disabled position the switc
48. next page T 57193 20713 Ws CE 12 Servicing should only be performed by a Qualified Service Technician CONTINUITY TEST DURING OPERATION This test is performed while the Combustion Blower is running at high speed during the Pre Purge operating state The test is performed on all three pressure switches Disconnect the two wires to each pressure switch one at a time check continuity and then reconnect the wires to that switch before testing the next switch 1 Turn off the circuit breaker that serves the water heater 2 Ensure the sensing tubes from each pressure switch are connected to the correct sensing port on the water heater 3 Disconnect the two wires for the switch to be tested 4 When testing the Blocked Exhaust and Blocked Air Intake Switches connect a jumper wire between the two wires disconnected This will temporarily prevent the Control System from locking out during the test When the test for these two switches is complete remove the jumper wire and reconnect the pressure switch wiring before moving on to the next switch 5 Restore power to the water heater if the water heater does not begin a heating cycle raise the Operating Set Point to activate a heating cycle 6 Using an ohm meter set for continuity testing check for continuity between the two wiring terminals at the pressure switch after the Combustion Blower has started and ramped up to high speed during the Pre Purge operating state Record the
49. ntroller has detected a low resistance or Alert occurred 0 mins ago short to earth ground or the tank The Powered Anode is shorted to earth ground or the tank Note This is an alert The unit will continue to heat water in press DOWN for more BACK ADVANCED CHECK REPAIR Bent anode shorting to tank Contamination solder loctite water Etc between anode top and surrounding metal Power anode shorted to ground at wire connection See Powered Anodes section shown under No Water section on Page 26 28 Servicing should only be performed by a Qualified Service Technician 10 TEMPERATURE PROBE SHORT UPPER OR LOWER Upper Temp Probe Short pi Fault occurred 0 mins ago The Upper or Lower Temperature Probe appears Upper Temperature Probe may be to be shorted very low resistance This fault code shorted Check connector and often means the connector has been corroded by resistance of Probe cleaning chemicals or other substances Press the Advanced button for press DOWN for more BACK ADVANCED CHECK REPAIR Make sure connector is clean and tight Check probe s resistance Replace the Temperature Probe if shorted resistance is below 390 Ohms See Temperature Probe section below TEMPERATURE PROBE This section of the Service Handbook provides information on the Temperature Probe The Temperature Probe contains the ECO energy cut out and a Temperature Sensor The Temperatu
50. o flow from the Flame Sensor to the Burner During ignition the burner flame must make complete and continuous contact with the Flame Sensor As the AC current flows from the Flame Sensor through the burner flame to the grounded Burner the AC current is rectified and becomes a DC current The current flowing between the Flame Sensor and Burner is DC micro amp current expressed as micro Amps Flame sensing current can be measured with a DC micro amp test meter see Tools Recommended on Page 2 CONTROL SYSTEM APPLIES AC CURRENT TO FLAME SENSOR FLAME SENSOR SPARK ee IGNITER CERAMIC INSULATOR METAL CONDUCTOR AC CURRENT FLOWS FROM THE FLAME SENSOR TO THE BURNER THE BURNER MUST BE GROUNDED FOR CURRENT TO FLOW DURING THIS PROCESS THE AC CURRENT IS RECTIFIED AND BECOMES A DC CURRENT DC MICRO AMP CURRENT THEN FLOWS BETWEEN THE FLAME SENSOR AND THE BURNER BURNER MUST BE GROUNDED MINIMUM FLAME SENSING CURRENT To prove burner flame during the Ignition Verification state the Control System monitors flame sensing current the DC micro amp pA current flowing through the Flame Sensor The Control System must sense a minimum amount of current to prove flame The minimum flame sensing current is 1 0 pA If flame sensing current does not reach 1 0 pA during ignition or falls below this amount
51. oft tubing from the Combustion Blower outlet sensing port 11 Using a socket wrench with a 77 deep well socket remove the four SUF 60120 six SUF 100150 100250 or eight SUF 119300 119500 77 nuts from the studs holding the burner plate in place 12 Slide the three burner ground wire eyelet connectors up and off of the studs Note These ground wires must be reinstalled when reinstalling the Burner Assembly 13 Ensure there are not any loose parts tools screws or objects of any kind on top of the water heater before removing the Burner Assembly as these objects could fall into the heat exchanger 14 Carefully lift the Burner Assembly straight up and out of the heater exchanger opening 15 Refer to the Flame Sensor and Spark Igniter sections of this Service Handbook for their servicing specifications COMBUSTION BLOWER BURNER INSTALLATION 1 Install new white fiber Burner Plate All Models and Flue Ring SUF 60120 100250 Models before re installing the Blower Burner Assembly To re install the Burner Assembly follow the steps for removal in reverse order Do not overtighten the 77 nuts Connect the supply gas line to the water heater on the heater side of the Main Gas Shut Off Valve Slowly open the Main Gas Shut Off Valve serving the water heater Turn on the electrical circuit breaker that serves the water heater Turn the water heater s Enable Disable switch to the Enable Position 9o c OY dx o
52. on all closed systems to control the harmful effects of thermal expansion Contact a local plumbing service agency to have a thermal expansion tank installed AIR REQUIREMENTS Carefully review the requirements for combustion and ventilation air in the Instruction Manual that came with the water heater Failure to meet these requirements when the water heater is installed or overlooking their importance when servicing the water heater often results in needless down time unnecessary parts replacement and customer dissatisfaction An inadequate supply of air for combustion and ventilation often causes operational problems A lack of combustion and ventilation air can create a negative ambient air pressure in the installed space which can lead to improper combustion and operational problems with pressure switches CONTAMINATED AIR Combustion air that is contaminated can greatly diminish the life span of the water heater and water heater components such as Igniters and Burners Propellants of aerosol sprays beauty shop supplies water softener chemicals and chemicals used in dry cleaning processes that are present in the combustion ventilation or ambient air can cause such damage Vapors from volatile compounds such as solvents cleaners chlorine based chemicals and refrigerants in addition to being highly flammable in many cases can also react to form highly corrosive substances such as acids inside the combustion chamber The results can be haz
53. or application or supply regulator may be operating improperly See Gas Pressure section below HIGH ALTITUDE The water heaters covered in this Service Handbook are certified for elevations up to 10 100 feet 3 078 meters For higher elevations call the toll free support phone number shown on the back cover of this Service Handbook for technical assistance GAS PRESSURE SPECIFICATIONS MODELS Natural Propane Natural Propane 60120 100250 60120 100250 119300 119400 119500 119300 119400 119500 Maximum Gas Supply 14 0 WC 14 0 WC 14 0 WC 14 0 WC Pressure 3 49 kPa 3 49 kPa 3 49 kPa 3 49 kPa Nominal Gas Supply 7 0 WC 11 0 WC 7 0 WC 11 0 WC Pressure 1 74 kPa 2 74 kPa 1 74 kPa 2 74 kPa 4 4 WC 8 5 WC 4 8 WC 8 5 WC 1 10 kPa 2 12 kPa 1 19 kPa 2 12 kPa Minimum Gas Supply Pressure Low Gas Press Switch Setting 0 WC 0 WC 0 WC 0 WC 0 kPa 0 kPa 0 kPa 0 kPa The Manifold Pressure is the factory setting and is not adjustable A negative pressure will be seen with just the blower running without the Gas Control Valve open Manifold Pressure Servicing should only be performed by a Qualified Service Technician 7 GAS SUPPLY SYSTEMS Low pressure building gas supply systems are defined as those systems that cannot under any circumstances exceed 14 W C 1 2 PSI Gauge These systems do not require additional pressure regulation Measurements should be taken to insure that gas pressures are st
54. or troubleshooting After the Combustion Blower is energized the Control System must confirm the Blower Prover switch contacts have closed see the Sequence Of Operation Flow Chart on Page 6 The Blocked Air Intake Switch and Blocked Exhaust Switch contacts must remain closed at all times If the Blower Prover switch contacts are closed during the Input Verification the Control System will lock out and display Blower Prover Failure on the UIM If the Blower Prover switch contacts do not close after the Combustion Blower is energized the Control System will lock out and display Blower Prover Open on the UIM If either the Blocked Air Intake Switch or Blocked Exhaust Switch contacts open at any time during a heating sequence the Control System will lock out and display Blocked Air Intake or Blocked Exhaust on the UIM Wires connecting to air switches are labeled near the terminals Ensure no mis wiring among terminals Servicing should only be performed by a Qualified Service Technician 11 PRESSURE SWITCH TESTS Complete pressure switch testing involves three procedures Continuity Test During Standby below Continuity Test During Operation on Page 13 Pressure Test During Operation on Page 13 thru Page 15 CONTINUITY TEST DURING STANDBY This test is performed while the Combustion Blower is not running with the water heater turned off This is a normal state continuity test of the contacts inside each pressure switch Disconnect t
55. ore BACK ADVANCED CHECK REPAIR Make sure connector is clean and tight Check probe s resistance Replace the Temperature Probe if open resistance exceeds 56 000 Ohms See Temperature Probe section under Temperature Probe Short Upper or Lower section on Page 29 32 Servicing should only be performed by a Qualified Service Technician VENTING This section of the Service Handbook is not a complete venting installation instruction Refer to the Instruction Manual that came with the water heater ensure the venting has been installed per all Instruction Manual requirements Costs to correct installation errors are not covered under the limited warranty GENERAL VENTING INFORMATION The water heaters covered in this Service Handbook are operationally equivalent to Category IV appliances and may be installed in either a Power Vent or Direct Vent configuration Category IV Appliance Category IV appliances operate with a positive vent exhaust static pressure and with vent gas temperatures low enough to produce condensate in the vent piping Power Vent Configuration Power Vent configurations derive all combustion air from the room where they are installed and discharge all flue gases to the outdoor atmosphere through a sealed vent exhaust pipe Power vent configurations have one vent pipe connected to the water heater which can be terminated in a vertical or horizontal arrangement Direct Vent Configuration Direct V
56. re Probe connects to the J9 Socket on the CCB see CCB Circuit Board Layout on Page 49 and CCB Connection Identification on Page 50 ECO HIGH TEMPERATURE LIMIT SWITCH The ECO energy cut out is a high temperature limit switch designed to protect against excessively high water temperatures inside the water heater s storage tank The ECO is a normally closed switch that opens on a rise in temperature The ECO switch is located inside the Temperature Probe two red wires The ECO temperature setting is non adjustable the contacts open at 201 F 94 and will close at approximately 140 F 60 The Control System constantly monitors the state of the ECO switch contacts If the ECO activates contacts open due to abnormally high water temperature the Control System will lock out and display Energy Cut Out ECO on the UIM Should the ECO activate the water temperature must drop below 140 F 60 C before the Control System can be reset Once the water temperature has cooled below this point the electrical circuit breaker that serves the water heater must be turned off and on again to reset the Control System TEMPERATURE SENSOR The Temperature Sensor located inside the Temperature Probe is a thermistor two black wires Thermistors are thermally sensitive resistors As the water temperature rises the resistance measured in ohms of the sensor will decrease as the temperature falls the resistance will increase see Temperatures
57. ressure reading taken reaches or exceeds the pressure shown in the Pressure Switch Settings Table on Page 14 and the switch contacts were opening during the Continuity Test During Operation on Page 13 the switch IS NOT defective and should not be replaced Ensure the condensate drain connected to the exhaust elbow on the water heater is not clogged and is draining freely Check for restrictions or blockage in the vent pipe check for too small of pipe installed too many equivalent feet and or too many elbows in the vent piping Check for low points in the vent pipe where water may be collecting and blocking the vent piping Check for any restrictions or debris at the vent termination outdoors Servicing should only be performed by a Qualified Service Technician 15 3 BLOWER PROVER OPEN CAUSES The control has detected an open Blower Prover Pressure Switch during operation Blower Prover Pressure Switch sensing tube Blower Prover Open Fault occurred 2 mins ago The blower prover switch remains open after the blower has been energized disconnected or kinked Loose or open wiring connections to Blower Call a service professional Prover Pressure Switch Your Company Name Here press DOWN for more BACK ADVANCED Blower not running when expected Blower Prover Pressure Switch not operating Replace Blower Prover Switch CHECK REPAIR The blower prover pressure switch will close its contacts on a pressure r
58. results open or closed 7 Repeat this procedure for each pressure switch 8 Turn off the circuit breaker that serves the water heater Confirm that all of the pressure switch wires are reconnected including the replacement part if necessary based on the Results Actions listed below Restore the electrical power to the water heater Reset the Operating Temperature Set Point if it was adjusted Run the water heater through a complete heating cycle before leaving to ensure it is operating properly Draw water from the nearest faucet to make sure that the water temperature does not pose a scalding hazard due to the increased temperature set points that were used in this procedure Results Actions Passed Results If the Blower Prover switch contacts activate close zero ohms direct short during this test the switch has passed this test If the Blocked Air Intake Switch and Blocked Exhaust Switch contacts remain closed during this test zero ohms direct short these switches have passed the test Failed Results If the Blower Prover switch contacts do not close during this test the Pressure Test During Operation below must be performed to determine if the switch is defective If the Blocked Air Intake Switch or Blocked Exhaust switch contacts open during this test the Pressure Test During Operation below must be performed to determine if the switch s is defective Proceed to the Pressure Test During Operation below PRESSURE TEST DURING OPERATIO
59. rs in the same gas supply system it is recommended that individual positive lock up gas pressure regulators be installed at each unit from the supply gas connection on the water heater Service notes The manifold gas pressure is factory set and cannot be adjusted in the field There are two pressure test ports on the water heater s 24 Volt Gas Control Valve see Figure below The Gas Control Valve outlet pressure test port is closest to the Combustion Blower see Figure below There is a needle valve in each test port that is opened closed with a small slotted screwdriver Turn the needle valve counter clockwise to open the test port valve and clockwise to close it The hose from the Gas Control Valve supply gas pressure test port should be connected to the positive pressure port of a manometer the other pressure port of a manometer should be left open There is usually a drop in supply gas pressure noticed when the water heater s 24 Volt Gas Control Valve opens during ignition The manifold pressure will go from a negative value during pre purge to near zero when gas is flowing A sustained drop in supply gas pressure of 1 5 W C or more during ignition may indicate the supply gas line is undersized If the water heater is experiencing a sustained drop in supply gas pressure of 1 5 W C or more and the water heater is experiencing repeated Ignition Failure fault conditions intermittent loss of flame or rough starting ensure the supply gas l
60. s Shut Off Valve serving the water heater Disconnect the supply gas line to the water heater on the heater side of the Main Gas Shut Off Valve mom pe Ie If the water heater has been installed in a Direct Vent configuration disconnect the Blocked Air Intake Switch sensing tube light blue soft tubing from the Air Intake Pipe Assembly and disconnect the intake air pipe at the intake air connection on the water heater by loosening the hose clamp closest to the Venturi and remove the Intake Air Assembly 6 If the water heater has been installed in a Non Direct Vent configuration disconnect the Blocked Air Intake Switch sensing tube light blue soft tubing from the Air Intake Pipe Assembly and disconnect the intake air pipe at the intake air connection on the water heater by loosening the hose clamp closest to the Venturi and remove the Intake Air Assembly 7T Unplug the ignition cable from the spark igniter and the yellow wire from the Flame Sensor 8 SUF 60120 100250 Models Disconnect the 3 Pin and 5 Pin plugs from the Combustion Blower Assembly SUF 119300 SUF 119500 Models Disconnect the blower power wires at the three spade connectors connecting the blower to the VFD and unplug the blower speed feedback connector from the wiring harness 9 Disconnect the 24 Volt power wires to the Gas Control Valve at the two spade connectors in the wiring harness to the valve 10 Disconnect the Blower Prover Switch sensing tube light blue s
61. socket on the blower assembly at all times SUF 60120 100250 Models only Disconnecting this plug will cause the Combustion Blower to stop If the electronic speed control is functioning properly Combustion Blower speed should noticeably reduce during the Trial For Ignition operating state If blower speed reduction does not occur during the Trial For Ignition operating state ensure the 5 pin plug from the CCB is securely plugged into the matching 5 pin socket on the blower assembly and that the J5 plug is securely plugged into the J5 socket on the CCB circuit board Perform a close visual inspection of the pins inside the plugs and sockets at the Combustion Blower and the CCB replace any worn or damaged wiring harnesses as necessary BLOWER HOUSING 3 WIRING i SOCKET BLOWER MOTOR AND ELECTRONIC SPEED CONTROL Servicing should only be performed by a Qualified Service Technician 39 BLOWER SPEED CONTROL SUF 119300 THRU 119500 The CCB monitors a feedback signal from a sensor that is installed on the blower The CCB interprets the pulse signal from the sensor and then sends a signal to the variable frequency drive VFD which in turn transmits the proper frequency to the blower to produce the proper blower speed and input Refer to the Variable Frequency Drive on next page for its operation Below is a chart for the blower roms and corresponding VFD Hertz Readings for those rpms displayed on the VFD Note These models are capable of
62. ssure exceeds 5 PSI often require multiple regulators to achieve desired pressures Systems in excess of 5 PSI building pressure should be designed by gas delivery professionals for best performance Water heaters connected to gas supply systems that exceed 14 W C 1 2 PSI Gauge must be equipped with a gas supply regulator capable of preventing the gas supplied to the unit from exceeding 14 W C under any upstream supply pressure or condition For Natural Gas SUF 60120 100250 models require a minimum gas supply pressure of 4 4 W C SUF 119300 119500 models require 4 8 W C and all models require 8 5 W C for propane gas The minimum supply pressure is measured while gas is flowing dynamic pressure along with all additional gas appliances operating on the same gas supply system The supply pressure should be measured with all gas fired appliances connected to the common main firing at full capacity If the supply pressure drops more than 1 5 W C 0 05 PSI Gauge when the water heater is operating at high fire rate then the supply gas system including the gas line and or the gas regulator may be restricted or undersized See Supply Gas Regulator section below The Gas Control Valve on all models has a maximum gas supply pressure limit of 14 W C 1 2 PSI Gauge The maximum supply pressure is measured while gas is not flowing static pressure to any appliances connected to the same gas supply system SUPPLY GAS REGULATOR The maxi
63. sure switch construction operation and the test procedures used to diagnose operational problems associated with pressure switches The pressure switches are identified with colored labels Blower Prover Switch is Green Blocked Air Intake Switch is Blue amp Blocked Exhaust Switch is Red CONTROL SYSTEM MONITORING The Control System monitors the state of the pressure switch contacts individually through three separate circuits see Wiring Diagrams on Page 52 amp Page 53 The state of the switch refers to whether the switch contacts are open or closed At the beginning of a heating sequence before the Combustion Blower is energized the Control System enters the Input Verification operating state During Input Verification the Control System monitors all three pressure switches to ensure their contacts are in the correct normal state The Blower Prover switch contacts must be open The contacts for the Blocked Air Intake Switch and Blocked Exhaust Switches must be closed If any of the pressure switch contacts are not in their correct normal state during Input Verification the Control System will lock out and display a fault message on the UIM indicating which pressure switch caused the fault condition If all system checks pass during the Input Verification operating state the Control System enters the Pre Purge operating state and energizes the Combustion Blower The Heater Status Screen and functionality of the water heater can be used f
64. t detect ignition 24 VDC PRESENT If 24 VDC is present on the Gas Control Valve connector during the beginning of an ignition cycle reinstall the connector and recycle the unit again Check the gas supply pressure during ignition using test procedure from Gas Pressure Test on Page 9 During the ignition cycle the gas supply pressure should drop about 0 5 to 1 5 W C when the Gas Control Valve icon appears if the Gas Control Valve is working If the gas supply pressure does not drop at the beginning of the ignition cycle the Gas Control Valve may be defective contact Commercial Technical Support A pressure drop of more than 1 5 W C indicates an issue with the gas supply pipe too long or too small bad regulator etc 24 VDC NOT DETECTED f 24 VDC is not detected on the connector terminals when the Gas Control Valve icon appears on the display contact Commercial Technical Support Servicing should only be performed by a Qualified Service Technician 19 5 BLOCKED AIR INTAKE CAUSES The Blocked Air Intake Switch has detected a possible restriction in the air intake pipe Blocked Air Intake Fault occurred 2 mins ago Restriction in air intake Check intake pipe and termination for blockage Call a service professional Your Company Name Here press DOWN for more BACK ADVANCED CHECK REPAIR Check pipe for restriction or excessive equivalent length See Instruction Manual for pipe size l
65. the ECO present call the toll free support phone number listed on the back cover of this manual for further assistance If the ohm meter shows no continuity open circuit between the two outside pins red wires and the tank temperature is known to be at or below 100 F 38 C replace the Temperature Probe Follow the draining and filling instructions in the maintenance section of the Instruction Manual that came with the water heater when replacing the Temperature Probe If the Control System continues to lock out displaying Energy Cut Out ECO on the UIM and the water temperature inside the water heater is becoming excessive at or above 201 F 94 C check water system piping ensure heat is not being added by any other heating appliances or heat sources If all these tests have been performed and the Control System continues to lock out call the toll free support phone number listed on the back cover of this manual for further assistance Servicing should only be performed by a Qualified Service Technician 31 11 TEMPERATURE PROBE OPEN UPPER OR LOWER CAUSES The Upper or Lower Temperature Probe appears to be open very high resistance This fault code often means the connector has been corroded by cleaning chemicals or other substances Lower Temp Probe Open Fault occurred 0 mins ago l Lower Temperature Probe may be O open Check connector and resistance of Probe Press the Advanced button for press DOWN for m
66. then shuts off with an Ignition Failure error message follow these steps Remove the connector from flame sense rod picture of connector showing location on unit Inspect the connector for corrosion Replace if corroded or damaged Remove Flame Sensor and clean metal end with steel wool Check insulator for soot cracks or other damage and replace if necessary CONTROL SYSTEM APPLIES AC CURRENT TO FLAME SENSOR ee FLAME SENSOR oo CERAMIC INSULATOR M METAL CONDUCTOR AC CURRENT FLOWS FROM THE FLAME SENSOR TO THE BURNER THE BURNER MUST BE GROUNDED FOR CURRENT TO FLOW DURING THIS PROCESS THE AC CURRENT IS RECTIFIED AND BECOMES A DC CURRENT DC MICRO AMP CURRENT THEN FLOWS BETWEEN THE FLAME SENSOR AND THE BURNER BURNER MUST BE GROUNDED Servicing should only be performed by a Qualified Service Technician 17 Reinsert connector on Flame Sensor and make sure the electrical connection is clean and tight Recycle unit again to start another ignition cycle If the burner ignites but the flame sense rod still fails to detect flame contact Commercial Technical Support BURNER DOES NOT IGNITE Failure to ignite no flame usually means a gas supply or Gas Control Valve problem If you do not see a brief blue flame through the sight glass during the ignition cycle at the moment the Gas Control Valve icon appears on the display fo
67. tion pressures in the Table above ON On Ensure all sensing tubes are properly routed and reconnected when testing is complete The pressure switches will not operate properly if there are leaks in the tubing Reset the Operating Temperature Set Point if it was adjusted Run the water heater through a complete heating cycle before leaving to ensure itis operating properly Draw water from the nearest faucet to make sure that the water temperature does not pose a scalding hazard due to the increased temperature set points that were used in this procedure Results Actions Blower Prover If the pressure reading taken at the Blower Prover switch sensing tube is at or above the activation pressure shown in the above Table AND the switch contacts did not close during the Continuity Test During Operation shown on Page 13 the switch is defective and must be replaced If the pressure reading taken does not reach or rise above the activation pressure in the above Table the pressure switch IS NOT defective and should not be replaced call the toll free phone number on the back cover of this Service Handbook for further technical assistance Have the complete Model Series and Serial number located on the water heater s rating label for the water heater being serviced on hand before calling 14 Servicing should only be performed by a Qualified Service Technician Blocked Air Intake Note these are negative pressures a vacuum If the pressure readin
68. tween the two inside pins black wires of the plug end from the Temperature Probe see Figures on next page Compare the measured resistance to the values given in Temperatures Table below Temperature Probes are very reliable and should only be replaced when The resistance is above 56 000 ohms open or below 390 ohms shorted The nature of the service problem is temperature control and the resistance readings are considerably 2596 different than the values in Temperatures Table below at the given temperature TEMPERATURES TEMPERATURE SENSOR o 288 ECO CONTINUITY TEST 1 Turn off the circuit breaker that serves the water heater 2 Remove the top cover on the water heater 3 Disconnect the four pin plug from the Temperature Probe outside the CCB enclosure in the middle see Figure on Page 31 Ensure tank temperature is less than 100 38 dump water to lower tank temperature if necessary 5 Using an ohm meter set the range for continuity testing 6 Check continuity between the two outside pins red wires of the plug end from the Temperature Probe see Figure on Page 31 30 Servicing should only be performed by a Qualified Service Technician Results Actions If the ohm meter shows continuity closed circuit between the two outside pins red wires the ECO switch has reset properly If the Control System continues to lock out displaying Energy Cut Out ECO on the UIM with continuity through
69. uch as hand tools screwdrivers pipe wrenches etc Long 8 10 T handle 1 8 inch hex allen key wrench for Combustion Blower removal and installation Hex Allen wrench sizes 5 32 1 8 1 4 and 5 16 for Burner and 24 Volt Gas Control Valve removal and installation Digital manometer Range 20 00 to 20 00 W C Resolution 0 01 W C Required to test pressure switch performance and supply gas pressure Digital Multi Meter capable of measuring AC DC Voltage Ohms DC micro amps pA flame sensing current see Flame Sensing Current Test on Page 25 2 Servicing should only be performed by a Qualified Service Technician INSTALLATION CONSIDERATIONS This section of the Service Handbook covers some of the critical installation requirements that when overlooked often result in operational problems down time and needless parts replacement Costs to correct installation errors are not covered under the limited warranty Ensure all installation requirements and instructions contained in the Instruction Manual that came with the water heater have been followed prior to performing any service procedures INSTRUCTION MANUAL Have a copy of the Instruction Manual that came with the water heater on hand for the model and series number being serviced Installation information given in this Service Handbook is not a complete installation instruction Installation information given in this Service Handbook has a limited focus as
70. using the same anode clean the bottom disc on the anode flange Apply Teflon tape pipe sealant to the new anode threads as shown below then insert anode and tighten securely Reconnect blue wire to anode brass terminal If necessary bend brass terminal tab up to allow for socket tool to fit properly REAR ANODE REPLACEMENT METHOD 1 m Remove the two blower connectors from the blower remove gas valve power plug and the two wires from the low gas pressure switch Remove air intake rubber boot from blower Disconnect gas supply connection from gas valve Remove the four 4 blower mounting screws to remove blower Using a T handle or hex head wrench usually provides adequate access Remove blower assembly with gas valve attached Repeat steps 1 6 from the Front Anode Replacement Method RE ASSEMBLY ge o 9 Replace blower gas valve assembly re install the four 4 blower mounting screws Re connect gas supply to the gas valve Re install the air intake rubber boot to the blower Connect the two blower connector wires connect the gas valve power supply plug and the two low gas pressure switch wires Turn on the water supply be sure tank is filled with water Check the power anode voltage to measure the tank potential Turn on the gas and power supply Restart the heater Servicing should only be performed by a Qualified Service Technician 27 9 ANODE SHORTED CAUSES Anode Shorted The co
71. ut the unit in enabled mode Increase the Operating Set Point if necessary to cause the water heater to have a call for heat Run the water heater through a complete heating cycle before leaving to ensure it is operating properly Return the Operating Set Point Temperature to its original setting Draw water from the nearest faucet to make sure that the water temperature does not pose a scalding hazard due to the increased temperature set points that were used in this procedure Servicing should only be performed by a Qualified Service Technician 2 BLOWER OPERATION ERROR CAUSES Blower Operation Error The Blower Prover Pressure Switch was detected Fault occurred 2 mins ago closed before blower operation Blower Prover Pressure Switch may have failed closed Check replace pressure switch Call a service professional Your Company Name Here press DOWN for more BACK ADVANCED CHECK REPAIR This switch is normally open and is used to prove blower operation This switch should be open when blower is not running Check continuity of pressure switch See Pressure Switch Tests section on Page 12 thru Page 15 PRESSURE SWITCHES The water heaters covered in this Service Handbook are factory equipped with four pressure switches including the Low Gas Pressure Switch Top View Figures on Page 5 shows the location of the three pressures switches on top of the water heater This section of the Service Handbook covers pres
72. vicing should only be performed by a Qualified Service Technician ELECTRICAL CONNECTIONS ALL MODELS The water heaters covered in this Service Handbook require a 120 VAC 10 single phase 60Hz 15 amp power supply and must also be electrically grounded in accordance with local codes or in the absence of local codes with the National Electrical Code ANSI NFPA 70 or the Canadian Electrical Code CSA C22 1 POWER FLUCTUATIONS AND ELECTRICAL NOISE The water heater s control system requires a source of stable clean electricity for proper operation Connecting the water heater to a branch circuit that is subject to fluctuations in voltage level or electrical line noise such as EMI electro magnetic interference or RFI radio frequency interference may cause erratic control system operation and malfunction A high quality power supply filter suppressor must be installed if the above conditions exist Call the technical support phone number listed on the back cover of this Service Handbook for more information Note Malfunctions caused by power supply and costs to install power supply filters are not covered under the limited warranty DEDICATED POWER WIRING AND BREAKERS Dedicated power supply wires ground wiring and dedicated circuit breakers often reduce electrical line noise and are required when installing the water heater ELECTRICAL WIRING All electrical work must be installed in accordance with the National Electrical Code ANSI

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