BoilerFaultCodesYour boiler has detected that water is not circulating correctly through the system to keep it cool.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Water circuit
What causes this fault?
This fault occurs when the boiler's internal sensors detect that heat is not being carried away from the burner quickly enough. The most common reason is a failed pump or a blockage in the pipework that prevents water from flowing through the system. If the water stays still for too long, it overheats, and the boiler shuts down as a safety precaution to prevent internal damage.
This issue often surfaces in autumn when the heating is turned back on after a long summer break, as pump components can seize up during periods of inactivity.
DIY fix possible
Check that the boiler pressure is between 1.0 and 1.5 bar on the gaugeEnsure all radiator valves and internal stop taps are fully openGently bleed air from your radiators using a bleed key
Find a Gas Safe engineer
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A boiler cover plan would cover faults like 2 — no call-out fees, no surprises.
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Ideal Maximiser SE 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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