How much does it cost to fix boiler error code 20-21?

Typical repair cost for the boiler 20-21 fault is £150-300 including labour.

20-21 High

Boiler Fault Code 20-21

Also written as 2021 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code 20-21 appears across 1 boiler brand and 1 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 that it is running too hot and has automatically switched itself off to prevent potential damage. (As reported on Remeha Quinta 30)

Pick your boiler brand for the 20-21 fix

Remeha 20-21 1 model

Source

Information for the 20-21 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 7 July 2026