BoilerFaultCodesYour boiler has shut itself down as a safety precaution because one of its internal sensors has detected a potential overheating or pressure issue.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: The safety devices have been activated (lockout)
What causes this fault?
This fault occurs when the boiler's internal temperature or pressure exceeds safe limits, triggering a total system shutdown to prevent damage. It is usually caused by a failure in the circulation pump or a blockage within the heat exchanger that stops water from moving through the unit quickly enough. When the water stays still for too long, it overheats almost instantly, causing the safety sensors to trip.
This issue is more frequent in autumn when the heating is first switched back on after a long summer break, as internal pumps can seize during periods of inactivity.
DIY fix possible
Check that your boiler pressure is between 1.0 and 1.5 barEnsure all radiator valves are open to allow water to flowPress the 'Reset' button on the control panel to see if the error clears
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 E13 — 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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