BoilerFaultCodesYour boiler has likely become too hot or water is not circulating correctly, causing it to shut down for safety.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Overheat thermostat has operated or primary flow switch has failed to operate
What causes this fault?
This fault occurs when the water inside the boiler reaches an unsafe temperature, triggering a safety sensor to shut the system down to prevent damage. The most common reasons are a pump failure that stops water from moving or a blockage in the pipework preventing heat from escaping the boiler.
This issue often appears when the heating is first turned on after summer, as the circulation pump can seize up after long periods of inactivity.
DIY fix possible
Rotate the selector switch to the 'Reset' position for 5 seconds, then back to its original setting.Check that all radiator valves are fully open to ensure water can flow.Verify that the system pressure is between 1 and 1.5 bar on the pressure gauge.
Find a Gas Safe engineer
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A boiler cover plan would cover faults like 70° neon flashing — 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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