BoilerFaultCodesYour boiler has likely overheated because the water isn't moving through the system properly or a sensor has detected an unsafe temperature.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: TEMPERATURE LIMITER. CONTROLLED BY THE HEATING THERMISTOR ON FLOW PIPE: CHECK HEATING THERMISTOR (MAY BE UNCLIPPED) OR THREE WAY VALVE FAULTY. FAULTY PUMP. LOW HEATING FLOW RATE.
What causes this fault?
This fault occurs when the boiler's internal sensors detect that the water temperature has exceeded a safe limit, causing the system to shut down for safety. The most common reason is a lack of water circulation, often caused by a failing pump or a stuck valve prevented water from leaving the boiler. It can also be caused by a simple sensor failure or a loose clip providing an inaccurate temperature reading.
This issue often surfaces when you first turn the heating back on in autumn, as internal moving parts like the pump or three-way valve can seize up after being idle throughout the summer.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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A boiler cover plan would cover faults like 14 — no call-out fees, no surprises.
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