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

Typical repair cost for the boiler 4A fault is £120-280 including labour.

4A High

Boiler Fault Code 4A

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code 4A 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 a sensor has detected that the water inside is getting too hot. (As reported on Ideal Maximiser SE)

Pick your boiler brand for the 4A fix

Ideal 4A 1 model

Source

Information for the 4A 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