BoilerFaultCodesGlow-worm S.07 Fault Code
Also written as S07 — same fault.
The Glow-worm S.07 fault code means: your boiler is briefly running the internal pump after the heating has switched off to cool down the internal components, which is a normal operation and typically not a fault.. It appears on 12 Glow-worm models in our database.
Technical description: pump overrun
What causes the Glow-worm S.07 fault?
This status appears when the boiler's internal computer determines that the heat exchanger is still very hot after a heating or hot water cycle. The pump continues to circulate water briefly to dissipate this residual heat and protect the internal components from overheating. Once the temperature drops to a safe level, the pump will stop and the display will return to normal.
DIY fix possible
Wait 5-10 minutes for the cycle to complete naturallyEnsure at least one radiator valve (bypass) is fully openCheck that your room thermostat is turned down
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Gas Safe Register →Glow-worm models that show the S.07 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Glow-worm S.07 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