BoilerFaultCodesYour boiler has shut itself down because it became too hot, likely due to a circulation problem or a component failure.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Overheat cut off device tripped. Thermostat, Overheat cut off device, Water differential pressure switch, or faulty Pump.
What causes this fault?
This fault occurs when the water inside the boiler reaches an unsafe temperature, triggering a safety sensor to shut the system down to prevent damage. The most common reasons are a pump failure that stops water from moving or a buildup of debris in the pipes that blocks flow. In some cases, the sensor itself may have failed and is incorrectly reporting that the boiler is overheating.
This issue often surfaces in autumn when the heating is turned back on for the first time, as pump components can seize up after being idle over the summer.
DIY fix possible
Locate the manual reset button on the overheat thermostat (usually behind the front panel or at the bottom).Press the button to reset the boiler once the unit has cooled down.Ensure all radiator valves are open and your heating system pump is running.
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