204 High

Boiler Fault Code 204

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code 204 appears across 5 boiler brands 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 has sensed that the water temperature has risen above the level it was set to reach, leading it to shut down for safety. (As reported on Worcester Bosch Greenstar 8000 Life & Style)

Pick your boiler brand for the 204 fix

Chaffoteaux 204 1 model Ideal 204 1 model Keston 204 4 models Myson 204 1 model Worcester Bosch 204 14 models

Source

Information for the 204 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