Boiler Fault Code F.451

Also written as F451 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026

Fault code F.451 appears across 1 boiler brand and 4 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 burner ignition or combustion process and has safely shut itself down to prevent operation until a technician checks it. (As reported on Viessmann Vitodens 200-W B2KF Combi)