Boiler Fault Code 373 8C

Also written as 3738C — same fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026

Fault code 373 8C appears across 1 boiler brand and 2 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has detected that it is getting too hot too often and has safely locked itself to prevent internal damage. (As reported on Worcester Bosch Greenstar CDi Compact)