BoilerFaultCodes S.61 High
Boiler Fault Code S.61
Also written as S61 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code S.61 appears across 1 boiler brand and 7 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler has failed a safety check during its start-up sequence because it cannot identify the gas type or verify the flame correctly. (As reported on Vaillant ecoTEC Pro / ecoTEC Plus)
Pick your boiler brand for the S.61 fix
Source
Information for the S.61 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