BoilerFaultCodes neon4 High
Boiler Fault Code neon4
Also written as NEON4 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code neon4 appears across 1 boiler brand and 11 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler is unable to light the pilot flame, which means it cannot fire up to provide heating or hot water. (As reported on Glow-worm Space Saver 30 40 50)
Pick your boiler brand for the neon4 fix
Source
Information for the neon4 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