BoilerFaultCodesYour boiler has sensed that water isn't moving through the unit as quickly as it should be, causing it to stop heating to prevent overheating.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Pump flow error
What causes this fault?
This fault occurs when the boiler detects that water is not circulating through the heat exchanger quickly enough to safely carry heat away. The most common reasons are a seized or failing internal pump, a blockage caused by sludge buildup, or air trapped within the pipework. Because the system cannot move the hot water out, it shuts down to prevent the internal components from overheating and sustaining damage.
This issue is more frequent during the first cold snap of autumn when a pump that has sat idle all summer struggles to start spinning again.
DIY fix possible
Ensure all radiator valves and isolation valves are fully openCheck that your system water pressure is between 1.0 and 1.5 bar on the displayBleed your radiators to remove any trapped air pockets
Find a Gas Safe engineer
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A boiler cover plan would cover faults like S.2 — 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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