BoilerFaultCodes Group 3 High
Boiler Fault Code Group 3
Also written as GROUP3 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code Group 3 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 has detected a critical internal error that prevents it from operating safely or correctly. (As reported on Worcester Bosch Greenstar CDi Compact)
Pick your boiler brand for the Group 3 fix
Source
Information for the Group 3 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