73 High

Boiler Fault Code 73

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code 73 appears across 3 boiler brands and 14 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 pump or motor is not receiving power or has stopped working, meaning it cannot circulate heat through your system. (As reported on Worcester Bosch Greenstar Utility 18/25)

Pick your boiler brand for the 73 fix

Alpha 73 10 models Vokera 73 3 models Worcester Bosch 73 1 model

Source

Information for the 73 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