F2 High

Boiler Fault Code F2

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code F2 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 a problem with the sensor that monitors the temperature of the water leaving the unit, causing it to shut down to prevent overheating. (As reported on Glow-worm Xtrafast 96 120)

Pick your boiler brand for the F2 fix

Ferroli F2 8 models Glow-worm F2 7 models Heatline F2 10 models Ideal F2 14 models Keston F2 8 models Saunier Duval F2 8 models Viessmann F2 9 models Worcester Bosch F2 1 model

Source

Information for the F2 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