E.04 – .02 High
Boiler Fault Code E.04 – .02
Also written as E0402 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code E.04 – .02 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 stopped working because it can no longer accurately measure the temperature of the water leaving the unit. (As reported on Baxi 200 / 400 Combi)
Pick your boiler brand for the E.04 – .02 fix
Source
Information for the E.04 – .02 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