BoilerFaultCodes F45 High
Boiler Fault Code F45
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code F45 appears across 1 boiler brand and 4 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 an issue with the sensor that monitors the temperature of the exhaust fumes, so it has safely shut down to prevent potential overheating. (As reported on Ferroli Maxima 35 S)
Pick your boiler brand for the F45 fix
Source
Information for the F45 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