BoilerFaultCodes F51 High
Boiler Fault Code F51
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code F51 appears across 1 boiler brand and 3 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler's main internal computer has developed a fault and can no longer control the heating or hot water safely. (As reported on Ferroli iBoiler 28)
Pick your boiler brand for the F51 fix
Source
Information for the F51 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