BoilerFaultCodes F.74 High
Boiler Fault Code F.74
Also written as F74 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code F.74 appears across 3 boiler brands and 40 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler has detected a problem with the sensor that monitors water pressure, meaning it cannot accurately tell if there is enough water in the system to run safely. (As reported on Vaillant ecoTEC Pro / ecoTEC Plus)
Pick your boiler brand for the F.74 fix
Source
Information for the F.74 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