BoilerFaultCodes S.6 High
Boiler Fault Code S.6
Also written as S6 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code S.6 appears across 1 boiler brand and 26 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler is trapped in a cooling-down cycle where the fan keeps running longer than necessary, preventing it from starting a new heating cycle. (As reported on Vaillant ecoMAX 613)
Pick your boiler brand for the S.6 fix
Source
Information for the S.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