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Eternal Water Heater Error Codes

In 2014 increasing problems with the Eternal heat exchanger and controls resulted in leaks and premature system failures. After a year of trying to correct the problems, Grand Hall, the parent company of Eternal Water Heaters, ceased operations in North America leaving their customers without warranty coverage, part replacements and technical resources.

You may be able to clear the Error Message simply by turning the hot water tap OFF, then ON again. If this does not clear the Error Message, try pushing the ON/OFF button OFF, then ON again. If the Error Message still remains, contact Hot Water Now! and arrange for a service call.

Eternal Hybrid Water Heater

Eternal Water Heater Repair

In some cases, we have the parts to make successful repairs. We are generally able to service and repair units that are not working properly, or are displaying an error code. Once the units develop a leak it’s time to consider replacing the system.

Self Monitoring

To assist with diagnosing an error, Eternal tankless water heaters have the ability to check their own operation continuously. If an error occurs, a message will flash on the digital monitor of the front panel. Please refer to the error code when scheduling service.

Before and After Eternal Water Heater Replacement
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Eternal Water Heater Error Codes

In 2014 increasing problems with the Eternal heat exchanger and controls resulted in leaks and premature system failures. After a year of trying to correct the problems, Grand Hall, the parent company of Eternal Water Heaters, ceased operations in North America leaving their customers without warranty coverage, part replacements and technical resources.

You may be able to clear the Error Message simply by turning the hot water tap OFF, then ON again. If this does not clear the Error Message, try pushing the ON/OFF button OFF, then ON again. If the Error Message still remains, contact Hot Water Now! and arrange for a service call.

Code Display Cause Remedy
E1Remaining flame detectedCall Hot Water Now! (720) 934-8711
E2Ignition failure - doesn't detect flame signalCheck gas line, ignitor, flame rod Check wire connection of 8p wire and ignitor wire Check ignition noise Check gas type and manifold pressure
E3Abnormal combustion - after detection of flame signal, system lose the signalCheck the gas supply in enough Check the gas valve Check wire connection of 8p wire and ignitor wire Check gas type and pressure are correct Check power supply for proper voltage
E4An outlet thermistor openCheck the outlet thermistor Check wire connection of 14p wire and thermistor wire
E5An outlet thermistor shortCheck the outlet thermistor Check wire connection of 14p wire and thermistor wire
E6A H/E thermistor openCheck the H/E thermistor Check wire connection of 14p wire and thermistor wire
E7A H/E thermistor shortCheck the H/E thermistor Check wire connection of 14p wire and thermistor wire
E8An inlet thermistor openCheck the inlet thermistor Check wire connection of 14p wire and thermistor wire
E9An inlet thermistor shortCheck the inlet thermistor Check wire connection of 14p wire and thermistor wire
E11A DC motor failureCheck DC motor Check wire connection of 6p wire
E13No filled water in tank or pressure switch failureCheck the water filled in tank Check water pressure switch Check connection of 14p wire and water pressure wire
E23Adjust control valve is not connectedCheck the adjust control valve movement noise Check wire connection of 16p wire and adjust valve wire
E24Mixing control valve is not connectedCheck the mixing control valve movement noise Check wire connection of 16p wire and mixing valve wire
E26Adjust control valve initialization failureCheck the adjust control valve movement noise Check wire connection of 16p wire and adjust valve wire
E27Mixing control valve initialization failureCheck the mixing control valve movement noise Check wire connection of 16p wire and mixing valve wire
E28Power line of main gas valve is openCheck the thermostat Check the thermal fuse Check the air pressure switch Check wire connection of gas valve, thermostat, thermal fuse and air pressure switch
E30Rotation of a DC fan is too highCall Hot Water Now! (720) 934-8711
E31Rotation of a DC fan is too lowCall Hot Water Now! (720) 934-8711
E36A controller failure concerning gas valveCall Hot Water Now! (720) 934-8711
E37Communication failure with SUB CPUCall Hot Water Now! (720) 934-8711
E38Subsidiary RAM failureCall Hot Water Now! (720) 934-8711
E39A controller failure concerning Subsidiary flame signalCall Hot Water Now! (720) 934-8711
E40Main RAM failureCall Hot Water Now! (720) 934-8711
E41A controller failure concerning flame signalCall Hot Water Now! (720) 934-8711
E42Main ROM failureCall Hot Water Now! (720) 934-8711
E43Main MUX errorCall Hot Water Now! (720) 934-8711
E47Intake Thermistor ShortCheck the intake thermistor Check wire connection of 14p wire and thermistor wire
E48Intake Thermistor ShortCheck the intake thermistor Check wire connection of 14p wire and thermistor wire
E49Intake Thermistor Detect Abnormal SituationCall Hot Water Now! (720) 934-8711
E50Room A Thermistor Short (only hydro heating)Check the room A thermistor Check wire connection of 12p wire and thermistor wire
E51Room A Thermistor Short (only hydro heating)Check the room A thermistor Check wire connection of 12p wire and thermistor wire
E52Room A Thermistor Short (only hydro heating)Check the room A thermistor Check wire connection of 12p wire and thermistor wire
E53Room A Thermistor Short (only hydro heating)Check the room A thermistor Check wire connection of 12p wire and thermistor wire
E54Current Leak on Gas Valve PowerCheck gas valve Check connection of gas valve wire
E56Less than 0.3gpm of water flow at recirculation mode and hydro heatingCheck flow sensor Check recirculation pump and loop Check connection of 14p wire and flow sensor wire
E57Pump is not connectedCheck wire connection of 8p wire and pump wire Check the pump
E58 / E59No response from ICC moduleCall Hot Water Now! (720) 934-8711
E93Master can't have any data on CAN lineCheck connection of 3p wire and MCU wire Check connection of termination wire and resistor(120Ω)
E94Sub can't have any signal from masterCheck connection of 3p wire and MCU wire Check connection of termination wire and resistor(120Ω)

Parts List for Model GU145(S)

KEY DESCRIPTION

  • 1. Panel, Front Assembly
  • 2. Panel, Top / Rear Assembly
  • 3. Panel, Rear
  • 4. Panel, Left Assembly
  • 5. Panel, Right Assembly (GU145(S))
  • 6. Panel, Bottom
  • 7. Mounting Bracket
  • 8. Wall Bracket
  • 9. Controller / Front
  • 10. T&P Relief Valve (Cash Acme)
  • 11. Vent Collar
  • 12. Vent Collar Packing
  • 13. Rubber Foot
  • 14. Drain Valve Assembly
  • 15. Main Power Cord
  • 16. Handle
  • 17. Condensing Nipple
  • 18. Mesh Screen
  • 19. Outdoor Venting Cap (Optional)
  • 20. Trap Cleaner Assembly
  • 21. Radial Blower Assembly
  • 22. Gas Valve
  • 23. Air Pressure Switch (GU145(S))
  • 24. Burner Assembly
  • 25. Main Controller (GU145(S))
  • 26. Cold Water Tube Assembly (GU145(S))
  • 27. Hot Water Tube Assembly (GU145(S))
  • 28. Flexible Silencer Kit
  • 29. Mixing Valve
  • 30. EC Adapter
  • 31. Water Pressure Switch

Eternal FAQ's

Eternal Water Heater Frequently Asked Service and Repair Questions

Get in Touch With Us

Learn more about our boiler and water heater repairs, installation, and maintenance services in Lakewood, contact our team at Hot Water Now! any time. We serve clients in:

  • Lakewood
  • Denver
  • Highlands Ranch
  • Littleton
  • Aurora