Burner On neon off Emergency

Glow-worm Burner On neon off Fault Code

Also written as BURNERONNEONOFF — same fault.

The Glow-worm Burner On neon off fault code means: your boiler's burner stays lit even when it should turn off, meaning it isn't responding to your thermostat or timer settings.. It appears on 4 Glow-worm models in our database.

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

Technical description: The burner will remain alight until switched off by the control thermostat, any remote control or the programmer.

What causes the Glow-worm Burner On neon off fault?

This fault occurs when the boiler loses its ability to regulate the flame, causing the burner to stay lit regardless of your heating settings. The most common reason is a malfunctioning main circuit board or a faulty gas valve that has become stuck in the open position. It can also be caused by a wiring error in your external thermostat or programmer that is continuously sending a 'heat on' signal.

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 Burner On neon off fault code

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

Source

Glow-worm Burner On neon off 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 27 April 2026