Noritz · Water Heater error code
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Guide · Water HeaterThe reset button is a high-limit (ECO) safety that opens when the water overheats. It does not fail by itself very often; something drove the water too hot: a thermostat stuck closed, an element shorted to the tank, or a loose, overheated wire. The wrong turn is pressing reset and leaving, or replacing only the upper thermostat without testing the elements and the wiring.
Guide · Water HeaterStandard residential electric tanks use two elements and two thermostats in non-simultaneous mode: the upper thermostat heats the top first, then hands power to the lower one. Totally cold water usually means a tripped high-limit (ECO), a dead upper element or a failed upper thermostat. Always find out why the ECO tripped before calling the job done.
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.
Noritz · Water Heater
05
Service due warning
Noritz · Water Heater
10
Combustion / exhaust problem
Noritz · Water Heater
11
Ignition failure
Noritz · Water Heater
12
Flame loss / weak flame
Noritz · Water Heater
14
Thermal fuse tripped (heat exchanger overheat)
Noritz · Water Heater
16
Outlet temperature spike (often scale)