S.59 Low

Boiler Fault Code S.59

Also written as S59 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code S.59 appears across 2 boiler brands and 3 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-check on its exhaust temperature sensor and is temporarily pausing its normal operation to complete this test. (As reported on Viessmann Vitodens 222-F B2TF)

Pick your boiler brand for the S.59 fix

Vaillant S.59 2 models Viessmann S.59 1 model

Source

Information for the S.59 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