How much does it cost to fix boiler error code 4C?

Typical repair cost for the boiler 4C fault is £120-300 including labour.

4C High

Boiler Fault Code 4C

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code 4C 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 has shut down because it has detected it is getting too hot or an internal safety fuse has blown. (As reported on Ideal Maximiser SE)

Pick your boiler brand for the 4C fix

Ideal 4C 1 model

Source

Information for the 4C 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