BoilerFaultCodesYour boiler has shut down because it has detected that there is either not enough water in the system or it 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: High limit or low water protection tripped
What causes this fault?
This fault occurs when the boiler's internal temperature rises too quickly or the system lacks the water pressure needed to move heat away from the burner. The most common reasons are a seized circulation pump that isn't moving the water, or a significant blockage in the pipework causing the unit to overheat rapidly.
This issue is more frequent in autumn when heating systems are switched back on after a summer of inactivity, which can cause the pump to seize.
DIY fix possible
Check the pressure gauge on the boiler front or underneath; it should be between 1 and 1.5 bar.If the pressure is too low, use the filling loop to top up the water level.Ensure all radiator valves are open and that the pump is not making unusual grinding noises.Press the reset button once the pressure is restored.
Find a Gas Safe engineer
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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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