BoilerFaultCodes FF1 High
Boiler Fault Code FF1
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code FF1 appears across 1 boiler brand and 1 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler has shut down because it detected that the exhaust gases are getting too hot, which is a safety feature to prevent damage to the system. (As reported on Viessmann Vitodens 025-W)
Pick your boiler brand for the FF1 fix
Source
Information for the FF1 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 7 July 2026