Boiler Fault Code E03-894

Also written as E03894 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026

Fault code E03-894 appears across 1 boiler brand 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 is struggling to get the right balance of air and gas to burn safely, which is often caused by the wrong internal setting or part being installed for the type of gas you are using. (As reported on Keston S30)