BoilerFaultCodes S.108 Low
Boiler Fault Code S.108
Also written as S108 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code S.108 appears across 1 boiler brand and 15 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler is currently performing a routine self-cleaning cycle to clear any fumes from the system before it attempts to ignite. (As reported on Vaillant ecoTEC plus)
Pick your boiler brand for the S.108 fix
Source
Information for the S.108 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