BoilerFaultCodesYour boiler has stopped working because the water returning from your radiators has become too hot, which usually means the water isn't circulating properly through the system.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Central heating return temperature is greater than90°C
What causes this fault?
This fault occurs when the water returning to the boiler is too hot, which happens when heat cannot be transferred away into your radiators effectively. The most common reasons are a pump failure that has stopped water from moving, or a blockage caused by a build-up of sludge and debris in the pipework.
This fault often appears during the first cold spell of autumn when the heating is turned back on after being idle all summer, which can cause internal pump components to seize.
DIY fix possible
Check that all radiator valves (TRVs) are fully openEnsure the boiler pressure is between 1.0 and 1.5 barCheck if any bypass valves in your pipework are accidentally closed
Find a Gas Safe engineer
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A boiler cover plan would cover faults like F24 — 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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