BoilerFaultCodesYour boiler has shut itself down as a safety precaution because it has detected a serious internal fault that could be related to combustion or basic operation.
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 unit is operating outside of its safe temperature or combustion limits. It is typically triggered because the system has overheated or failed to ignite correctly, forcing the boiler to shut down to prevent damage. The most common reasons include a failing limit thermostat, a blocked heat exchanger, or an issue with the gas supply components.
This fault is more frequent during the first cold snap of autumn when boilers are switched back on after being idle, as internal mechanical parts like the gas valve can become stuck.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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A boiler cover plan would cover faults like E31 — 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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