BoilerFaultCodes S.10 Low
Boiler Fault Code S.10
Also written as S10 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code S.10 appears across 3 boiler brands and 53 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler is simply letting you know that it has detected you have turned on a hot tap and it is currently working to heat your water. (As reported on Vaillant ecoTEC pro)
Pick your boiler brand for the S.10 fix
Source
Information for the S.10 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 31 August 2026