BoilerFaultCodesYour boiler has shut down because it has detected a temperature that is too high, often caused by a blockage or a pump failure.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Limit thermostat fault
What causes this fault?
This fault occurs when the water inside the boiler exceeds a safe temperature, triggering a safety switch to shut the system down. The most common reasons are a pump that has stopped moving water around the system or a blockage in the heat exchanger that prevents heat from escaping.
This fault is more frequent when you first turn the heating back on in autumn, as circulating pumps often seize up after being inactive all summer.
DIY fix possible
Check that all radiator valves are fully openEnsure the system water pressure is between 1 and 1.5 barTurn the selector switch to 'OFF/RESET' for a few seconds and then back to 'ON'
Find a Gas Safe engineer
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A boiler cover plan would cover faults like AL20 — no call-out fees, no surprises.
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Vokera Mynute 10E 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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