How much does it cost to fix boiler error code 401?

Typical repair cost for the boiler 401 fault is £280-500 including labour.

401 High

Boiler Fault Code 401

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code 401 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's internal computer brain has experienced a malfunction and can no longer communicate with the heating system. (As reported on Ideal Ideal Classic SE15P FF)

Pick your boiler brand for the 401 fix

Ideal 401 2 models

Source

Information for the 401 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