BoilerFaultCodes 004E High
Boiler Fault Code 004E
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 004E appears across 1 boiler brand and 6 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler has detected a flame when it shouldn't be there, but it has already cleared the error itself and should be safe to continue running. (As reported on Navien NCB)
Pick your boiler brand for the 004E fix
Source
Information for the 004E 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