BoilerFaultCodesYour boiler has sensed that the water inside is Getting too hot and has shut down to prevent damage.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Flow sensor temperature exceeded
What causes this fault?
This fault occurs when the water leaving the boiler reaches an unsafe temperature because it isn't moving through the system fast enough. The most common reasons are a failing pump that can't push the water round, or a build-up of debris and sludge that has partially blocked the internal pipework.
This issue often comes to light in autumn when the heating is first turned on after summer, as the internal pump can seize up during long periods of inactivity.
DIY fix possible
Check all radiator valves are fully open to allow water flowEnsure the boiler pressure gauge is between 1.0 and 1.5 barRestart the boiler using the reset dial or button
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 E18 — no call-out fees, no surprises.
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Vokera Pinnacle 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.
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