F3 High

Boiler Fault Code F3

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code F3 appears across 8 boiler brands and 65 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 fan that pushes exhaust gases out of your home, causing the system to shut down for safety. (As reported on Ideal Logic Code Combi ESP1)

Pick your boiler brand for the F3 fix

Alpha F3 4 models Ferroli F3 8 models Glow-worm F3 5 models Heatline F3 10 models Ideal F3 17 models Keston F3 8 models Saunier Duval F3 4 models Viessmann F3 9 models

Source

Information for the F3 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