BoilerFaultCodes GEB90 Medium
Boiler Fault Code GEB90
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code GEB90 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 Your boiler is flagging an issue with the mounting bracket used for an external flue installation, often indicating that the flue pipe is not securely fixed or supported correctly. (As reported on Grant Vortex)
Pick your boiler brand for the GEB90 fix
Source
Information for the GEB90 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