How much does it cost to fix boiler error code Neon 3 lit?

Typical repair cost for the boiler Neon 3 lit fault is £180-£450 including labour.

Neon 3 lit High

Boiler Fault Code Neon 3 lit

Also written as NEON3LIT — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code Neon 3 lit appears across 2 boiler brands and 4 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 internal electrical communication fault which is preventing it from starting up safely. (As reported on Glow-worm Ultimate3)

Pick your boiler brand for the Neon 3 lit fix

Glow-worm Neon 3 lit 2 models Saunier Duval Neon 3 lit 2 models

Source

Information for the Neon 3 lit 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