BoilerFaultCodes F.078 High
Boiler Fault Code F.078
Also written as F078 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code F.078 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 electronic brain is having trouble communicating with an external control accessory, preventing the system from operating correctly. (As reported on Vaillant ecoTEC plus)
Pick your boiler brand for the F.078 fix
Source
Information for the F.078 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