BoilerFaultCodesTechnical description
Flue thermistor fault
What causes this fault?
This fault occurs when the internal sensor responsible for monitoring the temperature of exhaust gases produces an incorrect reading or fails entirely. The most common reason is that the sensor has degraded over time or developed a short circuit, leading the boiler to shut down to prevent the unit from overheating or exhausting dangerous fumes.
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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