BoilerFaultCodesYour boiler is repeatedly shutting itself down as a safety precaution because it is becoming too hot.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Number of safety temperature cut off
What causes this fault?
This fault occurs when the boiler's internal safety sensors detect that the water temperature has risen too quickly or peaked beyond safe limits multiple times. It is usually caused by a lack of water flow, often due to a failing pump or a blockage of sludge and debris inside the main heating unit. Because the heat cannot be carried away into your radiators fast enough, the system shuts down to prevent the metal components from warping or cracking.
This issue often comes to light during the first cold spell of autumn, when a pump that has been idle all summer fails to start or struggles to push water through a cold, stagnant system.
DIY fix possible
Check that your home's radiator valves are fully open to allow water to flowEnsure your thermostat and programmer are calling for heatCheck that the boiler pressure gauge is in the green zone (usually 1 to 1.5 bar)
Find a Gas Safe engineer
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Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like D.60 — no call-out fees, no surprises.
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Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
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