BoilerFaultCodesYour boiler has become too hot and has shut itself down as a safety precaution to prevent damage.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Boiler overheat tripped
What causes this fault?
This fault occurs when the water inside the boiler exceeds a safe temperature limit, triggering a safety sensor to cut the power. The most common reasons are a pump failure preventing water from circulating or a blockage caused by sludge and debris inside the central heating pipework. In some cases, it can be caused by air trapped in the system or a faulty sensor providing an incorrect reading.
This issue often surfaces during the first cold spell of autumn when the heating is turned on after being dormant all summer, which can cause internal pumps to seize.
DIY fix possible
Check that your radiator valves are open and not turned to zero.Ensure your system water pressure is between 1 and 1.5 bar on the gauge.Turn the selector switch to the reset position for five seconds and then back to 'onn'.
Find a Gas Safe engineer
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Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like 2 red flashes — no call-out fees, no surprises.
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Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
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