BoilerFaultCodesTechnical description
Over heat cut off activated | Cause: Maximum temperature exceeded
What causes this fault?
This fault occurs when the water inside the boiler gets too hot, triggering a safety switch to prevent damage. The most common reason is that the water isn't moving through the system quickly enough, often due to a pump failure or a blockage in the pipework. It can also happen if the sensors that monitor temperature become faulty and send the wrong information to the boiler control board.
This issue often appears when you first turn the heating back on in autumn, as internal pump parts can seize up after being idle over the summer.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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