BoilerFaultCodes F.346 High
Boiler Fault Code F.346
Also written as F346 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code F.346 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 is struggling to automatically adjust its fuel-to-air balance, so it has safely shut down to prevent inefficient or unsafe burning. (As reported on Viessmann Vitodens 100-W WB1A)
Pick your boiler brand for the F.346 fix
Source
Information for the F.346 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