BoilerFaultCodesYour boiler has become too hot and has automatically shut down to prevent damage or safety issues.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Indicates that the overheat thermostat has tripped.
What causes this fault?
This fault occurs when the water inside the heat exchanger reaches a temperature that is dangerously high, triggering a safety switch to cut off the gas. The most common reasons are a pump failure preventing water from moving through the system or a blockage caused by a build-up of sludge and debris. It can also be caused by a faulty sensor that is incorrectly reporting the temperature to the control board.
This issue is more common during the first cold snap of autumn when a pump that has been idle all summer fails to restart or struggles to move cold, thickened system sludge.
DIY fix possible
Wait for the boiler to cool down completely (at least 30 minutes).Check that all radiator valves are open and not blocked.Press the overheat reset button located on the controls behind the front panel.Check if the pump is running or if there is a system blockage if it trips again.
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