BoilerFaultCodesYour boiler has shut down because it is heating up much faster than it should, which usually means the water isn't moving through the system properly.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Safety switch off temperature is rising to fast
What causes this fault?
This fault occurs when the boiler detects that the internal temperature is rising too quickly, triggering a safety shutdown to prevent overheating. It is usually caused by a blockage in the pipes or a failing pump that prevents hot water from leaving the boiler quickly enough. Essentially, the heat can't escape into your radiators, so it builds up inside the unit almost instantly.
This fault is more common in autumn when heating systems are turned back on after a long summer break, as internal pump parts can seize up from lack of use.
DIY fix possible
Check that your boiler pressure is between 1.0 and 1.5 bar on the digital displayEnsure all radiator valves are fully open to allow water to flowPress the reset button (flame symbol with a cross) to see if the fault 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 F.24 — 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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