BoilerFaultCodes E407 High
Boiler Fault Code E407
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code E407 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 struggling to accurately measure the temperature of the water circulating through your radiators, so it has safely shut itself down to prevent potential overheating. (As reported on Navien NCB)
Pick your boiler brand for the E407 fix
Source
Information for the E407 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