BoilerFaultCodesYour boiler has shut itself down because it detected it was getting too hot, likely due to a lack of water circulation or a blockage.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Boiler safety cutoff device operated to prevent damage through overheating. Main burner goes out during a demand.
What causes this fault?
This fault occurs when the water inside the boiler reaches a dangerously high temperature, triggering a safety switch to prevent damage. The most common reason is that the pump has failed or is stuck, meaning heat cannot be carried away from the boiler and into your radiators or hot water tank. It can also be caused by a build-up of sludge or debris blocking the internal pipework, which restricts the necessary flow of water.
This issue is most frequent when turning the heating back on for the first time in autumn, as pump internal components can seize up after being idle throughout the summer.
DIY fix possible
Check that your system water pressure is between 1 and 1.5 barEnsure all radiator valves and the boiler isolation valves are fully openPress the reset button once to see if the boiler restarts
Find a Gas Safe engineer
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A boiler cover plan would cover faults like Red neon on the Reset Button — no call-out fees, no surprises.
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