Navien · Water Heater error code
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Guide · Water HeaterThermopile-powered gas controls report their state by counting blinks, then pausing. Reading the code correctly tells you whether the problem is the pilot, low thermopile power, overheating, a sensor or the control itself. Only codes confirmed by two sources are listed; everything gas-side is diagnosed here and referred to a licensed gas technician.
Guide · Water HeaterPower-vent tanks add a 120 V blower, an air pressure switch and often a vent temperature limit. Most no-heat calls are electrical supply, a kinked or water-filled pressure switch tube, condensate in the blower, or a restricted vent. The tech checks power and the low-voltage safety chain and inspects visually; gas valve, burner, igniter/flame sensor and vent repairs are referred to a licensed gas technician.
Guide · Water HeaterCrossover-type recirculation systems use the cold line as the return: a temperature-sensing valve under the farthest sink lets cooled water in the hot line flow into the cold line until hot water arrives. Depending on the kit, the pump mounts at the water heater (with the valve at the sink) or under the sink itself. Placement at the farthest fixture and correct hot/cold orientation are what make it work.
Navien · Water Heater
E003
Ignition failure
Navien · Water Heater
E004
False flame detected
Navien · Water Heater
E012
Flame loss during operation
Navien · Water Heater
E016
Overheating
Navien · Water Heater
E030
Exhaust overheat
Navien · Water Heater
E046
Limit control abnormality