BoilerFaultCodesYour boiler is firing but doesn't detect the water warming up as expected, so it has shut down to prevent overheating.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Dry fire: Flow/return temperature sensor temperature change too small
What causes this fault?
This fault occurs when the boiler's internal computer fires the burner but fails to see a significant enough rise in water temperature within the pipes. The most common reason is a lacks of water flow through the heat exchanger, often caused by a failing pump or a blockage that prevents heat from being carried away. It can also be caused by faulty sensors giving incorrect readings or air trapped within the system.
DIY fix possible
Check the pressure gauge and top up the system to between 1 and 1.5 bar if it is lowEnsure all radiator valves and the boiler isolation valves are fully openBleed all radiators to remove trapped air pockets
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.83 — 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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