BoilerFaultCodesTechnical description
Controls without flow temperature sensor (low loss header) - System flow temperature sensor lead break
What causes this fault?
This fault occurs when the boiler's control board can no longer detect a signal from the temperature sensor located on the main pipework. The most common reason is a physical break in the internal wiring or a sensor that has failed due to age, preventing the boiler from knowing how hot the water is as it leaves the unit. Because the system cannot safely monitor the heat, it shuts down to prevent damage.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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