BoilerFaultCodes F.347 High
Boiler Fault Code F.347
Also written as F347 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code F.347 appears across 1 boiler brand and 3 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler is unable to drain away the water it creates during normal operation, so it has safely shut itself down to prevent internal damage. (As reported on Vaillant ecoTEC plus)
Pick your boiler brand for the F.347 fix
Source
Information for the F.347 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