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S.02 on Glow-worm Flexicom cx

Your boiler is simply preparing its internal pump before starting the heating or hot water process.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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

pump pre-run

What causes this fault?

This isn't actually a fault, but rather a brief status message where the boiler circulates water internally before firing the burner. It ensures that any trapped heat is cleared and proper flow is established to protect the heat exchanger from overheating. Once this short preparation phase is complete, your heating or hot water will begin as normal.

DIY fix possible

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

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Related fault codes

S.00View →S.01View →S.03View →S.04View →

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