BoilerFaultCodesYour boiler has shut itself down for safety because a critical fault or overheating has been detected.
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 safety sensors detect that the system is getting dangerously hot or that water isn't moving through the unit correctly. The most common reasons are a failed pump that isn't circulating water or a faulty limit thermostat that is incorrectly reporting a high temperature.
This issue often surfaces when the heating is first turned on in autumn, as pumps can seize up after being inactive throughout the summer.
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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A boiler cover plan would cover faults like E27 — 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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