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 – check that any valves to the heating circuit have not been shut down, no air in the system and that the water pressure is correct
What causes this fault?
This fault occurs when the water inside the heat exchanger reaches a dangerously high temperature, triggering a safety sensor to cut the power. The most common reasons are a lack of water flow caused by a failed pump, a blockage in the pipework, or air trapped within the system preventing heat from being moved away from the burner.
This issue often appears when the heating is first turned on after summer, as internal pump components can seize up during long periods of inactivity.
DIY fix possible
Check that the boiler pressure is between 1.0 and 1.5 bar on the gauge.Ensure all radiator valves and internal isolation valves are fully open.Bleed your radiators to remove any trapped air pockets from the system.
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Keston C36 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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