How much does it cost to fix boiler error code 4.1?

Typical repair cost for the boiler 4.1 fault is £120-250 including labour.

4.1 High

Boiler Fault Code 4.1

Also written as 41 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code 4.1 appears across 2 boiler brands 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 an issue with how it is communicating with its internal safety systems or controls, preventing it from starting up safely. (As reported on Baxi 825 Combi)

Pick your boiler brand for the 4.1 fix

Atmos 4.1 1 model Baxi 4.1 1 model

Source

Information for the 4.1 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 7 July 2026