BoilerFaultCodes C4273 High
Boiler Fault Code C4273
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code C4273 appears across 1 boiler brand and 3 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler has stopped working because the internal fan has been running non-stop for too long, causing the system to shut down for safety. (As reported on Worcester Bosch CDi Classic)
Pick your boiler brand for the C4273 fix
Source
Information for the C4273 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