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: Overheat thermostat fault detected by diagnostic feature.
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 failed pump that isn't moving water away fast enough or a blockage in the heat exchanger that traps heat. Sometimes, it can also be caused by a build-up of air or sludge in the system restricting flow.
This fault is more common when the heating is first turned on after summer, as pump components can seize up during long periods of inactivity.
DIY fix possible
Check that your radiator valves are open to allow water to flowEnsure the system pressure is within the normal range (usually 1 to 1.5 bar)Locate the manual reset button on the control box and press it firmly
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 Overheat — no call-out fees, no surprises.
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Ideal Concord CXC 48 116 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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