BoilerFaultCodesYour boiler has shut down because the water inside the heating system has become too hot and cannot circulate properly.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Temperature is too high during central heating demand.
What causes this fault?
This fault occurs when the water inside the heat exchanger reaches a dangerously high temperature because it cannot move through the system effectively. The most common reasons are a failed circulation pump that is no longer pushing water around or a blockage caused by a build-up of sludge and debris in the pipework.
This issue is more frequent during the first cold snap of autumn when pumps that have been idle all summer often seize up or struggle to move heavy sludge.
DIY fix possible
Check that all radiator valves and internal doors are open to allow water flow.Ensure your system pressure is between 1.0 and 1.5 bar on the digital display.Restart the boiler once it has cooled down to see if the error clears.
Find a Gas Safe engineer
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A boiler cover plan would cover faults like F001 — 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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