235 High

Boiler Fault Code 235

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code 235 appears across 1 boiler brand and 21 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler’s internal control parts are speaking different languages because a newer component has been installed that is incompatible with the older system. (As reported on Worcester Bosch GB162)

Pick your boiler brand for the 235 fix

Worcester Bosch 235 21 models

Source

Information for the 235 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