BoilerFaultCodesYour boiler has shut down because the water inside it has become too hot, triggered by a safety sensor to prevent damage.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Over temperature on primary water circuit
What causes this fault?
This fault occurs when the water inside the boiler exceeds a safe temperature limit, causing the safety sensors to shut the system down. It is usually caused by a failure to move heat away from the burner, often due to a broken internal pump or a blockage in the pipework. In some cases, a build-up of limescale or sludge can restrict water flow, leading to rapid overheating.
This issue often surfaces during the first heavy use of the heating in autumn, as pumps can seize up after being inactive over the summer months.
DIY fix possible
Check that your radiator valves are open and not turned to zero.Ensure there is enough water pressure by checking the gauge is between 1 and 1.5 bar.Wait 15 minutes for the unit to cool down and try pressing the reset button.
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A boiler cover plan would cover faults like 14 — no call-out fees, no surprises.
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