BoilerFaultCodesYour boiler has switched itself off because the water inside has become too hot too quickly.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Burner off because of high flow temperature
What causes this fault?
This fault occurs when heat cannot move away from the boiler's heat exchanger quickly enough, causing the internal water temperature to spike instantly. The most common reasons are a failed pump that isn't circulating the water or a physical blockage like sludge or limescale restricting the flow. Sometimes, a faulty sensor simply misreads the temperature and triggers the shutdown as a safety precaution.
This issue often comes to light during the first cold snap of autumn when the heating system is pushed to work hard after being idle all summer.
DIY fix possible
Check that all radiator valves are fully open to allow water to circulate.Ensure your magnetic system filter is not blocked or restricted.Check that the boiler pressure is between 1.0 and 1.5 bar on the pressure gauge.
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 9 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Remeha W40 60 is discontinued — time for a new one?
Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
Affiliate links — we may earn a commission at no extra cost to you.