BoilerFaultCodesYour boiler has shut down completely because a safety sensor has detected that the system is overheating.
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 water inside the boiler reaches an unsafe temperature, triggering a safety switch to prevent damage. The most common reasons are a pump failure that stops water from moving or a blockage in the system causing heat to build up too quickly.
This issue often appears when the heating is first switched on after summer, as pump components can seize up during long periods of inactivity.
DIY fix possible
Check that your radiator valves are open and not turned to zero.Verify that the boiler pressure gauge is between 1 and 1.5 bar; top up if necessary.Attempt to reset the boiler by turning the selector switch to the 'OFF/RESET' position and then back to 'ON'.
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 E02 — 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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