S.24 Low

Glow-worm S.24 Fault Code

Also written as S24 — same fault.

The Glow-worm S.24 fault code means: your boiler is operating normally and is currently firing the burner to provide heating or hot water; this is a status message, not an error.. It appears on 9 Glow-worm models 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: burner on

What causes the Glow-worm S.24 fault?

This code appears when the boiler's internal controls have successfully confirmed that gas and air are present to ignite the burner. It signifies that the system is currently active and burning fuel to reach the temperature requested by your thermostat or hot water tap. This is part of the boiler's normal operating sequence rather than a mechanical failure.

DIY fix possible

Check your room thermostat or programmer if you did not expect the heating to be onEnsure your taps are fully closedNo action is required as this is a normal operational code

Find a Gas Safe engineer

Search the official register for a qualified engineer in your area.

Gas Safe Register →

Glow-worm models that show the S.24 fault code

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

Source

Glow-worm S.24 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