S.0 Low

Glow-worm S.0 Fault Code

Also written as S0 — same fault.

The Glow-worm S.0 fault code means: your boiler is currently in standby mode because it has reached the target temperature set on your thermostat or programmer and is not currently being asked to provide heat.. It appears on 15 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: Heatingmode:Norequirement

DIY fix possible

Check your room thermostat is set to a higher temperature than the current room temperatureEnsure your heating programmer or timer is set to 'On' for the current time periodNo further action is required as the boiler is operating normally

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Glow-worm models that show the S.0 fault code

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

Source

Glow-worm S.0 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 31 August 2026