BoilerFaultCodes F.450 High
Boiler Fault Code F.450
Also written as F450 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code F.450 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's internal computer has encountered a software timing error, causing it to lose its place during its normal operating sequence. (As reported on Viessmann Vitodens 222-F B2TF)
Pick your boiler brand for the F.450 fix
Source
Information for the F.450 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