How much does it cost to fix boiler error code G31?

Typical repair cost for the boiler G31 fault is £120-250 including labour.

G31 High

Boiler Fault Code G31

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code G31 appears across 2 boiler brands and 2 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is detecting an issue with the pressure of the gas being supplied to the burner, which is preventing it from firing up safely. (As reported on Sime Ecomfort Plus HE)

Pick your boiler brand for the G31 fix

Biasi G31 1 model Sime G31 1 model

Source

Information for the G31 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 7 July 2026