BoilerFaultCodes F.344 High
Boiler Fault Code F.344
Also written as F344 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code F.344 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 has lost the digital settings it needs to safely control the flame, meaning it cannot operate until these are reset or the internal hardware is replaced. (As reported on Vaillant ecoTEC Plus 836)
Pick your boiler brand for the F.344 fix
Source
Information for the F.344 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