BoilerFaultCodes E.02 – .21 High
Boiler Fault Code E.02 – .21
Also written as E0221 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code E.02 – .21 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's electronic settings have been altered or are misconfigured, preventing it from operating correctly. (As reported on Baxi 200 / 400 Combi)
Pick your boiler brand for the E.02 – .21 fix
Source
Information for the E.02 – .21 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