F0 High

Boiler Fault Code F0

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code F0 appears across 7 boiler brands and 78 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler's internal computer has encountered a communication error or software glitch that is preventing it from running safely. (As reported on Worcester Bosch Greenstar 30HE)

Pick your boiler brand for the F0 fix

Alpha F0 6 models Glow-worm F0 4 models Heatline F0 10 models Keston F0 8 models Saunier Duval F0 2 models Viessmann F0 9 models Worcester Bosch F0 39 models

Source

Information for the F0 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