BoilerFaultCodes 203 Low
Boiler Fault Code 203
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 203 appears across 1 boiler brand and 24 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler is currently sitting in standby mode because it has reached its target temperature and is waiting for a new request for heating or hot water. (As reported on Worcester Bosch GB162)
Pick your boiler brand for the 203 fix
Source
Information for the 203 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