BoilerFaultCodesYour boiler has detected that the water inside is getting too hot and has shut itself down as a safety precaution.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Boiler is not working for central heating or hot water and the display shows ‘HHHHH:::::AAAAA ’ (flashing).
What causes this fault?
This fault occurs when the water within the boiler's heat exchanger reaches an unsafe temperature, triggering a safety cutout to prevent damage. The most common reason is a lack of water flow, often caused by a failing pump or a blockage in the pipework that prevents heat from being carried away from the unit. It can also be triggered by a faulty internal sensor that is incorrectly reporting the temperature to the control board.
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 and not turned to zero.Verify that the system water pressure is between 1 and 1.5 bar on the gauge.Allow the boiler to cool down for 20 minutes and press the Reset button.
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