How much does it cost to fix boiler error code E.04 – .05?

Typical repair cost for the boiler E.04 – .05 fault is £90-180 including labour.

E.04 – .05 High

Boiler Fault Code E.04 – .05

Also written as E0405 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code E.04 – .05 appears across 1 boiler brand and 24 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 a problem with a safety sensor that monitors the temperature of the exhaust gases, causing the system to lock out. (As reported on Baxi 200 / 400 Combi)

Pick your boiler brand for the E.04 – .05 fix

Baxi E.04 – .05 24 models

Source

Information for the E.04 – .05 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