BoilerFaultCodes F.427 High
Boiler Fault Code F.427
Also written as F427 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code F.427 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 stopped working because it has detected an issue with an external control signal that tells it to turn on or off. (As reported on Viessmann Vitodens 100-W WB1A)
Pick your boiler brand for the F.427 fix
Source
Information for the F.427 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