BoilerFaultCodesYour boiler has detected that water is not circulating correctly through the system, preventing it from firing up to heat your home or water.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Primary flow switch not operated or requires investigation.
What causes this fault?
This fault occurs when the boiler's internal sensors do not detect enough water movement to operate safely, usually because the pump has failed or the flow switch is stuck. The most common reason is that the rubber diaphragm inside the flow valve has perished or the pump has become seized after a period of inactivity.
This issue often appears in early autumn when the heating is turned on for the first time after summer, as the pump can seize during the warmer months.
DIY fix possible
Check that the central heating valves under the boiler are fully openEnsure all radiator valves are turned on and not stuckCheck the boiler pressure gauge and top it up to 1.5 bar if it is too low
Find a Gas Safe engineer
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A boiler cover plan would cover faults like 30° neon flashing — no call-out fees, no surprises.
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Potterton Performa 28i 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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