BoilerFaultCodesYour boiler has detected an internal temperature issue and has locked itself out 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: Failed temperature – try resetting the boiler
What causes this fault?
This fault occurs when the water inside the heat exchanger reaches an unsafe temperature, triggering a safety shutdown. It is usually caused by a lack of water flow, often due to a seized internal pump or a blockage within the system's pipework. If the pump cannot move the hot water away from the burner quickly enough, the heat builds up rapidly and trips the overheat sensor.
This issue often appears when the heating is first turned on after summer, as the circulation pump can seize up during long periods of inactivity.
DIY fix possible
Locate the reset button on the front control panelPress and hold the reset button for at least 5 secondsCheck that your radiator valves are open and that the system pressure is between 1 and 1.5 bar
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A boiler cover plan would cover faults like 02 — no call-out fees, no surprises.
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Ravenheat CSI 120 is discontinued — time for a new one?
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