Noritz · 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 HeaterMany tankless complaints are water-side: flow below the activation threshold, a clogged inlet screen, low-flow aerators, or scale in the heat exchanger. Gas supply, venting and combustion codes are blocked: diagnose and refer. Read the code first, then work the water side.
Guide · Water HeaterThe sacrificial anode protects the tank from corrosion. When it is mostly consumed (core wire exposed), replace it. Powered anodes are an option where odor is a problem.
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)