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

Typical repair cost for the boiler Error 20 fault is £120-220 including labour.

Error 20 High

Boiler Fault Code Error 20

Also written as ERROR20 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code Error 20 appears across 2 boiler brands and 2 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 read how hot the internal water temperature is. (As reported on Potterton Titanium Combi)

Pick your boiler brand for the Error 20 fix

Keston Error 20 1 model Potterton Error 20 1 model

Source

Information for the Error 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 7 July 2026