BoilerFaultCodes E012 High
Boiler Fault Code E012
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code E012 appears across 2 boiler brands and 9 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler has stopped because the flame inside has gone out and will not stay lit, meaning you currently have no heating or hot water. (As reported on Navien NCB)
Pick your boiler brand for the E012 fix
Source
Information for the E012 fault code is sourced from the official service / installation manual for each model that displays it. Read more about how we source fault codes →
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026