BoilerFaultCodes E03-893 High
Boiler Fault Code E03-893
Also written as E03893 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code E03-893 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 has detected an incorrect internal air-to-gas ratio, which prevents it from firing up safely. (As reported on Keston K170)
Pick your boiler brand for the E03-893 fix
Source
Information for the E03-893 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