How much does it cost to fix boiler error code E.01 – .20?

Typical repair cost for the boiler E.01 – .20 fault is £120-350 including labour.

E.01 – .20 High

Boiler Fault Code E.01 – .20

Also written as E0120 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code E.01 – .20 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 switched itself off because it has become too hot inside, likely due to water not flowing correctly or a faulty internal sensor. (As reported on Baxi 200 / 400 Combi)

Pick your boiler brand for the E.01 – .20 fix

Baxi E.01 – .20 24 models

Source

Information for the E.01 – .20 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