How much does it cost to fix boiler error code GWB90?

Typical repair cost for the boiler GWB90 fault is £100-200 including labour.

GWB90 Medium

Boiler Fault Code GWB90

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code GWB90 appears across 1 boiler brand and 1 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning This code indicates that the mounting bracket securing your boiler to the wall is either loose, damaged, or incorrectly installed, which could cause the unit to become unstable. (As reported on Grant Vortex)

Pick your boiler brand for the GWB90 fix

Grant GWB90 1 model

Source

Information for the GWB90 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