BoilerFaultCodesTechnical description
Flue thermistor fault
What causes this fault?
This fault occurs when the sensor responsible for measuring the heat of the gases leaving your chimney sends an incorrect or missing signal to the boiler's computer. The most common reason is that the sensor itself has developed an electrical failure or the wiring connecting it to the main control board has become loose or damaged.
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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