BoilerFaultCodes F.6 High
Boiler Fault Code F.6
Also written as F6 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code F.6 appears across 1 boiler brand and 4 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler has stopped working because a sensor that measures the temperature of the water leaving the unit has stopped sending a reliable signal. (As reported on Vaillant ecoMAX Pro 28E)
Pick your boiler brand for the F.6 fix
Source
Information for the F.6 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 27 April 2026