BoilerFaultCodesYour boiler has shut down because the water returning from your radiators has become too hot, usually due to a lack of water flow 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 t° >90°C
What causes this fault?
This fault occurs when the water returning to the boiler is nearly boiling, which usually means the heat isn't being carried away to your radiators quickly enough. The most common reason is a failing pump that can't circulate the water, or a blockage in the system pipework that is restricting the flow.
This fault is more common when the heating is first turned on after summer, as circulation pumps can often seize up after long periods of inactivity.
DIY fix possible
Ensure all radiator valves (TRVs) are turned to the highest settingCheck that the boiler pressure is between 1.0 and 1.5 bar on the gaugeGently bleed your radiators to remove trapped air
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like F24 — no call-out fees, no surprises.
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