BoilerFaultCodes F.105 High
Boiler Fault Code F.105
Also written as F105 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code F.105 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's computer has lost the specific internal calibration settings required to mix the gas and air correctly, meaning it cannot safely start up. (As reported on Vaillant ecoTEC Plus 832)
Pick your boiler brand for the F.105 fix
Source
Information for the F.105 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