BoilerFaultCodesTechnical description
Central heating sensor is overheating
What causes this fault?
This fault occurs when the water temperature within the boiler's heat exchanger rises too high or too quickly, triggering the safety sensor to shut down the system. The most common reasons are a faulty temp sensor giving a false reading, a pump failure that stops water from moving, or a blockage caused by sludge and limescale buildup.
This issue often appears in autumn when the heating is turned back on for the first time, as pump parts can seize up after being idle through 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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