NEON2 High

Glow-worm NEON2 Fault Code

The Glow-worm NEON2 fault code means: your boiler is receiving a request to turn on the heating or hot water, but it has not yet successfully fired the burner.. It appears on 15 Glow-worm models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: DEMAND ON

What causes the Glow-worm NEON2 fault?

This fault occurs when the boiler recognizes you want heating or hot water but fails to complete its internal safety checks to ignite the flame. It is usually caused by a mechanical failure in the fan or the air pressure switch, which prevents the boiler from proving it can safely expel exhaust gases. As a result, the system stays in a 'holding' pattern and refuses to fire the burner for safety reasons.

This issue often surfaces during the first cold spell of autumn when a fan that has sat idle all summer struggles to spin up to the required speed.

Typical repair cost £120-350 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Glow-worm models that show the NEON2 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Glow-worm NEON2 fault code information on this page is sourced and cross-checked against the official Glow-worm service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026