BoilerFaultCodesTechnical description
Boiler overheat tripped
What causes this fault?
This fault occurs when the water inside the heat exchanger reaches an unsafe temperature, triggering a safety sensor to cut the power. The most common reasons are a pump failure preventing water from moving through the system or a blockage such as lime scale or sludge restricting the flow. Sometimes, the overheat thermostat itself has simply become faulty and is sending a false signal to the control board.
This fault is more common in winter when the heating is first turned on after a long summer break, as circulating pumps can often seize or stick during months of inactivity.
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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