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

Typical repair cost for the boiler E 20 fault is £150-300 including labour.

E 20 Emergency

Boiler Fault Code E 20

Also written as E20 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code E 20 appears across 2 boiler brands and 6 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 flame even though it has commanded the gas supply to shut off, meaning it has safely locked itself to prevent a potential hazard. (As reported on Ariston Euro Combi 30 MFFI)

Pick your boiler brand for the E 20 fix

Ariston E 20 5 models Chaffoteaux E 20 1 model

Source

Information for the E 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