BoilerFaultCodesYour boiler is simply preparing its internal pump before starting the heating or hot water process.
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.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like S.02 — no call-out fees, no surprises.
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Glow-worm Flexicom cx is discontinued — time for a new one?
Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
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