BoilerFaultCodesYour boiler has switched itself off to prevent overheating because the system is getting too hot or the water is not circulating properly.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Control thermostat overheat or pump failure cut-off devices operated. Faulty pump.
What causes this fault?
This fault occurs when the water inside the boiler reaches an unsafe temperature, triggering a safety switch to shut the system down. The most common reasons are a pump that has stopped circulating water or a blockage in the pipework that prevents heat from escaping the boiler. Just like an engine overheating, the boiler stops to prevent internal damage to its components.
This issue often appears when the heating is turned back on for the first time in autumn, as pumps can seize up after being idle throughout the summer months.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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