Your boiler has detected that there is not enough water pressure or the water isn't moving around the system properly to operate safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Primary water circulation fault - Low system pressure or pump failure.
What causes this fault?
This fault occurs when the boiler's internal sensors detect that water is not flowly quickly or pressurized enough to safely carry heat away from the burner. The most common reasons are a loss of system pressure due to a minor leak or a mechanical failure of the pump which prevents water from circulating through your radiators.
This issue often surfaces when the heating is turned on for the first time in autumn, as pump components can seize up after sitting idle during the summer months.
DIY fix possible
Check the pressure gauge on the front of the boiler; it should be between 1 and 1.5 bar.If it is below 1 bar, use the filling loop underneath the boiler to top up the water pressure.Ensure all radiator valves are open and that the pump isn't blocked by gently bleeding your radiators.
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 neon illuminated (tap/radiator symbols) — no call-out fees, no surprises.
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Potterton Performa 24 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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