BoilerFaultCodesYour boiler is simply performing a routine preparation step by running its internal pump before ignition to ensure safe water flow.
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 status occurs when the boiler detects a demand for heat and starts the internal pump to move water through the heat exchanger. It is a vital safety check designed to ensure there is sufficient water flow before the burner ignites to prevent the system from overheating. Once the electronics confirm the water is circulating correctly, the boiler will proceed to the ignition stage.
DIY fix possible
This fault may be fixable without an engineer. Check your manual first.
Find a Gas Safe engineer
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A boiler cover plan would cover faults like S.02 — no call-out fees, no surprises.
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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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