BoilerFaultCodesYour boiler has shut down because the water inside is getting much hotter than it should be, which is often caused by a blockage or a pump failure preventing the heat from moving away.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Flow temperature too high
What causes this fault?
This fault happens when the water leaving the boiler heats up too quickly or exceeds safe limits, causing the system to shut down for safety. It is usually caused by a pump failure or a blockage within the pipes that prevents hot water from circulating away from the boiler's heat exchanger. In many cases, it is the result of 'sludge' or debris building up over time and restricting the flow of water.
This fault is most common during the first cold spell of autumn when the heating is turned back on after being idle all summer, which can cause internal pump parts to seize.
DIY fix possible
Check that all radiator valves are fully open to allow water to circulate.Ensure your boiler pressure gauge is between 1 and 1.5 bar; top up if necessary.Check if any external bypass valves or magnetic system filters are blocked.
Find a Gas Safe engineer
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A boiler cover plan would cover faults like 2965 B — 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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