BoilerFaultCodesTechnical description
Heating thermistor (NTC) fault
What causes this fault?
This fault occurs when the internal sensor responsible for tracking the temperature of your radiators fails to send a reliable signal to the main control board. The most common reason is that the sensor's internal electrical resistance has drifted out of range due to age or heat degradation, though loose or corroded wiring can also trigger the alert.
This fault is more common in autumn when the heating is turned on for the first time after summer, as the sudden thermal expansion can cause a weakened sensor to fail completely.
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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