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Burner Lit LED on Glow-worm Micron 40FF

Your boiler is working exactly as it should and is currently heating the water for your radiators or taps.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

What the manual says

Manufacturer manual

Indicates that the burner is lit and the boiler is operating normally.

From this model's manual
Verified against the Micron 50 Ff installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

What causes this fault?

This is not actually a fault, but a status indicator showing that the gas valve has opened and the burner has successfully ignited. It confirms that the internal sensors have detected a flame and the boiler is now generating heat for your central heating or hot water. If this light is on, the system is performing its primary function exactly as intended.

DIY fix possible

This fault may be fixable without an engineer. Check your manual first.

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