Green 'Running' light Low

Glow-worm Green 'Running' light Fault Code

Also written as GREENRUNNINGLIGHT — same fault.

The Glow-worm Green 'Running' light fault code means: your boiler is working normally and is currently heating up water for your taps or your radiators.. It appears on 1 Glow-worm model in our database.

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.

Technical description: Indicates the appliance is running/operational (typically during hot water demand).

What causes the Glow-worm Green 'Running' light fault?

This is not a fault, but rather a positive status indicator showing that the boiler is actively burning gas to generate heat. It appears when you turn on a hot tap or when your thermostat signals that the house needs warming up. Once the demand for heat or hot water is met, this light will typically turn off as the boiler enters standby mode.

DIY fix possible

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

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Glow-worm models that show the Green 'Running' light fault code

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

Source

Glow-worm Green 'Running' light 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