BoilerFaultCodesTechnical description
Flue NTC (Negative Temperature Coefficient) operation error
What causes this fault?
This fault occurs when the sensor monitoring your boiler's exhaust gases detects temperatures that are high enough to potentially damage the plastic internal components. The most common reasons are a buildup of debris inside the main heat exchanger restricting heat transfer or a simple electrical failure of the sensor itself. In some cases, it can also be triggered if the boiler is over-firing or if the burner has not been serviced and cleaned recently.
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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