S.108 Low

Glow-worm S.108 Fault Code

Also written as S108 — same fault.

The Glow-worm S.108 fault code means: your boiler is currently running a standard safety procedure to clear out any leftover air or gases before it ignites, which is a normal part of its operation.. 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: Purging the combustion chamber, fan in operation

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 S.108 fault code

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

Source

Glow-worm S.108 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