BoilerFaultCodesYour boiler has shut down because a sensor detected that the water inside has become far too hot.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Primary thermistor (NTC) overtemperature
What causes this fault?
This fault occurs when the water within the boiler's main heat exchanger reaches an unsafe temperature, triggering a safety shutdown to prevent damage. The most common reasons are a pump failure preventing water from moving around the system or a build-up of sludge and debris that blocks the flow.
This issue often surfaces in autumn when the heating is first turned on after summer, as the circulation pump can become seized during long periods of inactivity.
DIY fix possible
Turn the boiler off at the electrical switch or dial.Ensure all radiator valves are fully open to allow heat to dissipate.Wait 20 minutes for the system to cool, then turn the boiler back on and rotate the mode selector to the 'reset' position.
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A boiler cover plan would cover faults like 07 — no call-out fees, no surprises.
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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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