BoilerFaultCodes F (Flashing) High
Boiler Fault Code F (Flashing)
Also written as FFLASHING — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code F (Flashing) appears across 1 boiler brand and 2 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 working and entered a safety shutdown mode, meaning it will not provide heating or hot water until it is reset or repaired. (As reported on Potterton Envoy 30)
Pick your boiler brand for the F (Flashing) fix
Source
Information for the F (Flashing) 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