SH Low

Boiler Fault Code SH

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code SH appears across 2 boiler brands and 6 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 in service mode, which is an intentional setting used by engineers to test the system and not a mechanical breakdown. (As reported on Ideal Logic Combi ESP1)

Pick your boiler brand for the SH fix

Ideal SH 5 models Worcester Bosch SH 1 model

Source

Information for the SH 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