Boiler Fault Code 3.C

Also written as 3C — same fault.

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

Fault code 3.C appears across 1 boiler brand and 1 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is heating up too quickly and has paused itself to prevent over-heating, which often suggests there is a problem with the water circulating through the system. (As reported on Worcester Bosch Greenstar CDi Compact)