BoilerFaultCodes E012 High
Boiler Fault Code E012
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code E012 appears across 1 boiler brand and 7 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler is trying to start up but is failing to light the flame, so it has safely stopped trying to prevent a gas build-up. (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 27 April 2026