How much does it cost to fix boiler error code Er 09?

Typical repair cost for the boiler Er 09 fault is £120-220 including labour.

Er 09 High

Boiler Fault Code Er 09

Also written as ER09 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 31 August 2026

Fault code Er 09 appears across 2 boiler brands and 10 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 a sensor measuring the temperature of the exhaust gases is not working correctly, which is preventing the system from running safely. (As reported on Biasi Advance Plus 16S 25S 30S)

Pick your boiler brand for the Er 09 fix

Biasi Er 09 9 models Johnson Starley Er 09 1 model

Source

Information for the Er 09 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 31 August 2026