Boiler Fault Code Neon 1

Also written as NEON1 — same fault.

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

Fault code Neon 1 appears across 3 boiler brands and 6 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 the internal fan system is already running or the air sensor is stuck before it should be, preventing the boiler from starting its ignition sequence safely. (As reported on Ideal Classic RS)