BoilerFaultCodes 2/3/3 High
Boiler Fault Code 2/3/3
Also written as 233 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 2/3/3 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's main computer control unit is reporting a serious internal hardware failure, meaning it can no longer safely operate your heating or hot water. (As reported on Worcester Bosch GB162)
Pick your boiler brand for the 2/3/3 fix
Source
Information for the 2/3/3 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 7 July 2026