BoilerFaultCodesYour boiler has lost communication with the temperature sensor that controls your second heating circuit, causing that specific zone to stop heating correctly.
This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.
Technical description: Mixer closes - Heating circuit M2 flow temperature sensor lead break
What causes this fault?
This fault occurs when the boiler can no longer receive data from the sensor monitoring the temperature of your second heating zone, such as underfloor heating. The most common reasons are a loose connection in the internal wiring, a broken cable, or the sensor itself failing due to age.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
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