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Manual 238-51306-00A REV 12/14

SERVICE

MANUAL

Troubleshooting Guide

and Instructions for Service

(To be performed ONLY by

qualified service providers)

Effective: December, 2014
ECO 7956

Models Covered

by This Manual:

UCG100H399*N
(*) Denotes Warranty Years

Ultra Low NOx Atmospheric Vent

Water Heaters with Direct Spark Ignition

Summary of Contents for UCG100H399

Page 1: ...NUAL Troubleshooting Guide and Instructions for Service To be performed ONLY by qualified service providers Effective December 2014 ECO 7956 Models Covered by This Manual UCG100H399 N Denotes Warranty...

Page 2: ...ce Procedure IV Gas Valve Replacement 27 Service Procedure V Blower Testing and Replacement 28 Service Procedure VI Flame Sensor Testing and Replacement 30 Service Procedure VII Spark Rod Gap Adjustme...

Page 3: ...ked combustion chamber This turbulence causes a thorough mixing of gas and air for optimum combustion The combustion gases then travel through a two pass flue system keeping the gases moving at a high...

Page 4: ...given component In some difficult to diagnose conditions it may be necessary to isolate the heater from the vent system to determine root cause Contact Technical support immediately if diagnosis is no...

Page 5: ...ion and blower operation x Reduced number of parts for servicing and wiring x Plug in wiring reduces chance of miswiring x Burner ignition with direct spark ignition A high voltage spark jumps from th...

Page 6: ...n Dia Relief Valve Open Shipping Weight lbs UCG100H399 399 000 100 77 8 10 52 55 69 63 30 28 63 1 1 657 Model Description Dimensions MM Model No Input Rate KW Storage Capacity Liters A Floor to Top of...

Page 7: ...nsor inside well for easy replacement of sensor Control Display Digital display 24 volts temperature Range 70 180 degree F Used to set tank temperature deg F or deg C show operating status display err...

Page 8: ...straight vent pipe in feet required for the intake 2 Add 5 feet of venting for every 90 elbow 3 Add 2 feet of venting for every 45 elbow 4 Total vent length cannot exceed Max Intake Vent Length on th...

Page 9: ...ormally closed opens then the ignition sequence will not start and an error code 67 Vent safety switch failed to close open will be shown on the display 5 Steady State Operation Burner continues to op...

Page 10: ...reset is accomplished by depressing the lower right button under Reset for 3 seconds 2 ERROR CODE 80 a If the top of the tank should exceed 207 F then the high limit control will shut off the burner a...

Page 11: ...at transformer across black and white wires should be 110 120 VAC Check line cord with volt meter Replace line cord if defective Verify secondary voltage at the control board Refer to control board i...

Page 12: ...proximately from metal ground with insulated pliers during the ignition cycle 3 second spark trial period Is there spark to ground Check resistance of high voltage cable Resistance should be 0 1 ohms...

Page 13: ...urrent in microamps when the burner is operating Step 3 Press the lower right Next button and the display will show flash and show the number of any Alert codes These are not currently used WARNING Th...

Page 14: ...n and the display will show the temperature sensor reading Step 6 End of screens in Diagnostic Mode Press Done button on lower left to exit Diagnostic Mode back to DHW setpoint in the User Mode NOTICE...

Page 15: ...ecked x If the line voltage is satisfactory check the output from the transformer to make sure it is 22 26 volts x Replace transformer or wiring if defective 53 AC Inputs phase reversed x Check the mo...

Page 16: ...sor is wired to the correct terminal x Make sure the ignition cable is not crossing the flame sensor wire or ignition ground wires x If problem persists and all other checks have been verified replace...

Page 17: ...ting and replacement section Replace sensor if needed Turn power ON to water heater Run water heater through heating cycle and verify proper operation Sensor temperature can be viewed when burner shut...

Page 18: ...water temperature over 200 F continued from previous page Once cause of overheating condition has been diagnosed and corrected the control may be reset x Reconnect and switch on power to the water he...

Page 19: ...982 4873 4767 110 4663 4562 4464 4368 4274 4183 4094 4006 3922 3839 120 3758 3679 3602 3527 3453 3382 3312 3244 3177 3112 130 3048 2986 2925 2866 2808 2752 2697 2643 2590 2538 140 2488 2439 2391 2344...

Page 20: ...ull sensor to remove do not remove well see picture Step 6 Install new sensor assembly into well and reinstall senor clip Step 7 Reconnect the sensor connector to the control board and route the wire...

Page 21: ...e between 7 14 W C static heater not running See illustrations at right Is gas supply pressure regulator adjustable to maintain proper and stable setting Inadequately sized regulator Adjust gas supply...

Page 22: ...during the flame establishing period Note Control display must show Heating for operating status Check to see brown and blue wires are properly connected to molex connectors on control harness Can you...

Page 23: ...m top of heater Step 5 From the gas valve disconnect the gas connection PVC intake venting Silicone tubing and wire harness Step 6 Disconnect wire harnesses flame sensor gas valve and blower Disconnec...

Page 24: ...re combustion assembly at the burner mounting insert using screws from step 7 on previous page Tighten screws evenly Step 3 Reconnect high voltage cable to spark rod flame sensor blower and gas valve...

Page 25: ...ess and silicone tubing Step 6 Disconnect wire harness from blower assembly Step 7 Remove the two screws holding each the spark rod and flame sensor in place long reach magnetic Phillips screw driver...

Page 26: ...ed by any of the above gasket replacement is not required Step 2 Install burner tube with gaskets into burner mounting insert Be sure gasket surfaces are free of debris Step 3 Reconnect the blower gas...

Page 27: ...bit located as shown below on the venturi mounting flange and remove gas valve from water heater Step 7 Remove any residual gasket material from blower and venturi mounting flange Step 8 Install new...

Page 28: ...blower motor Is there 6 to 3 0 amps Is blower wheel secured to blower motor shaft Call for technical support Replace blower See Blower Replacement Procedure Refer to ignition module control board illu...

Page 29: ...lower flange mounting screws 5 32 Allen wrench and remove blower from transition flange Step 9 Remove any residual gasket material from venturi mounting flange and transition flange Step 10 Install ne...

Page 30: ...there 24 VAC across brown and blue wires coming out of the control harness Flame sensing circuit O K Call for technical support With flame sensor disconnected from ignition module check continuity to...

Page 31: ...crews magnetic tip long reach Phillips screw driver and remove flame sensor gasket from transition base flange Step 6 Remove any residual gasket material from transition base flange Step 7 Install new...

Page 32: ...od and burner tube Acceptable spark gap is from 3 16 to 1 4 see photo below Step 3 If spark gap is not between 3 16 to 1 4 the spark rod may be carefully bent by supporting the end near the ceramic in...

Page 33: ...d Step 5 Remove the 2 mounting screws magnetic tip long reach Phillips screw driver and remove spark rod gasket from transition base flange Step 6 Remove any residual gasket material from transition b...

Page 34: ...Note It may be necessary to identify wires for proper re connection Step 6 Depress the plastic tabs on the bottom side of the control board first Step 7 Tilt the control panel and slide control hook...

Page 35: ...tion Contact your plumbing professional to correct this issue Step 4 When no blockage or downdraft issues are present check the continuity of the switch see photo below If there is no continuity prese...

Page 36: ...s of the original diameter approximately diameter replacement is recommended If any of the steel core of the anode is exposed replacement is recommended Step 6 Upon completion of inspection or subsequ...

Page 37: ...on the right Step 4 After removing the screw pull the display out of the enclosure Step 5 Once the display is removed disconnect the two mating plugs Step 6 Connect in new display and replace into the...

Page 38: ...ections are different sizes to prevent interchanging Step 5 Remove the 2 nuts 7 16 nut driver holding the transformer in place and remove transformer from control panel see photo below Step 6 Install...

Page 39: ...to remove the anode rods for servicing 18 min Vent Tables Intake Only Model Number Max Intake Vent Length feet 3 Max Intake Vent Length feet 4 UCG100H399 25 50 WARNING The UCG100H399 model is not appr...

Page 40: ..._____ Venturi Setting from Bottom in Turns ____________________________ Electrical Line Voltage ________________ Low Voltage ________________ Flame Sense A ___________ Polarity ____________________ Sp...

Page 41: ...Model 8 Control Display 9 Front Cold Water Inlet 10 Plastic Hole Closure 11 No Handle Brass Drain Valve 12 Cleanout Access Cover 13 Screw 5 16 18 x HH Grade 14 Cleanout Cover 15 T P specify model 16 H...

Page 42: ...sket Burner specify model 5 Gasket Screw 17 Burner specify model 6 Transistion Tube 18 Burner Mount Assembly 7 Gasket Blower Transition 19 Sight Glass Assembly 8 Gasket Transition Tube 20 Gasket Sight...

Page 43: ...red under one or more of the following U S Patents 5 277 171 5 341 770 5 372 185 5 485 879 5 574 822 5 596 952 5 660 165 5 682 666 5 761 379 5 943 984 5 954 492 5 988 117 6 056 542 6 142 216 6 442 178...

Page 44: ...p Notes ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ _________...

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