BoilerFaultCodesYour boiler has shut itself down completely because the internal water temperature has become too hot.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Safety thermostat to protect against overheating of the water. Should this device operate, both the pilot and main burner are extinguished.
What causes this fault?
This fault occurs when water inside the boiler reaches a dangerous temperature, triggering a mechanical safety switch to cut off the gas for your protection. The most common reasons are a failed pump failing to move hot water away from the heat exchanger, or a buildup of limescale and sludge creating 'hot spots' within the unit.
This issue often surfaces during the first cold snap of autumn when a heating pump that has been sitting idle all summer fails to start up correctly.
DIY fix possible
Wait for the boiler to cool down for at least 30 minutesLocate the reset button on the underside of the boiler casingPress the button firmly to reset the thermostat and relight the pilot light following the instructions on the boiler door
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 Limit Thermostat — no call-out fees, no surprises.
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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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