Boiler Fault Code 2/3/9

Also written as 239 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026

Fault code 2/3/9 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 internal computer is experiencing a major electronic failure, preventing it from starting or maintaining its normal operation. (As reported on Worcester Bosch GB162)