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GWH 635 ESO Tech Support
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GWH 635 ESO Technical Support
Troubleshoot With No Error Codes
Q.
Burners Do Not Ignite When Hot Water Is Turned On?
Q.
Water Is Too Hot?
Q.
Water Is Not Hot Enough?
Q.
Low Water Flow/Pressure?
Q.
Hot Water Temperature Fluctuates At Tap; Unit Deactivates?
Q.
Noisy Burner/Heater During Operation?
Troubleshooting Error Codes
Please note:
If there is a problem with the installation, venting or operation of the unit, the heater will communicate the source by these error codes.
Q.
A2
Fault in the overheat cutoff fuse (white overheat wire/fuse that wraps around the heat exchanger).
Q.
A7
Hot Water Temperature Sensor fault
Q.
A9
Hot water temperature sensor not sensing correct selected temperature. This error code may flash on display while heater continues to run or it may shut off the heater requiring resetting of the error code.
Q.
C1
Fan rotation too low at start-up.
Q.
C6
Fan rotation too low during operation.
Q.
C7
No rotational speed sensor signal from fan.
Q.
CA
Water flow signal over specified maximum value.
Q.
E1
Over-temperature detected by temperature sensor on hot water pipe.
Q.
E2
Cold water temperature sensor fault.
Q.
E9
Temperature limiter open circuit.
Q.
EA
No flame ionization detected with water flow.
Q.
EC
Ionization failure while burning. This error code indicates the heater is not sensing good flame quality.
Q.
EO
Internal software/hardware failure.
Q.
F7
Ionization error at standby.
Q.
FA
Gas leakage error. Gas valve circuit not closing properly.
Q.
8E
Electronic noise in the control unit.
GWH 635 ESO
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GWH 635 ESO Tech Support
GWH 635 ESO Tech Support
Troubleshoot
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Note: Specifications and product information subject to change without notice.