BoilerFaultCodesYour boiler has shut down completely because one of its safety sensors has detected a problem with the internal temperature or pressure.
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 hardware detects that the heat exchanger has become dangerously hot. The most common reason is a lack of water flow or a blockage within the system, which prevents heat from being carried away from the boiler quickly enough.
This issue often surfaces during the first cold spell of autumn when the heating is turned back on and pumps or valves may have seized after months of inactivity.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
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A boiler cover plan would cover faults like E16 — 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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