BoilerFaultCodesYour boiler has shut down because it has detected it is getting too hot, usually due to a lack of water flow or a circulation blockage.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Overheat fault
What causes this fault?
This fault occurs because the internal sensors have detected the water inside the boiler is reaching a dangerously high temperature, triggering an automatic shutdown to prevent damage. The most common reason is that the water isn't moving through the system quickly enough, often due to a failed pump, a blockage in the pipework, or a build-up of sludge in the heat exchanger.
This issue often surfaces during the first cold spell of autumn when the heating is turned back on after months of inactivity, as pumps can seize up during the summer.
DIY fix possible
Check if your radiator valves are open to ensure water can circulate.Check the boiler pressure gauge and top it up to 1.5 bar if it is low.Gently press the reset button on the front of the boiler.
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A boiler cover plan would cover faults like 05 — no call-out fees, no surprises.
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