Your boiler has detected a problem with the sensor that measures the temperature of the water going to your radiators, causing the system to stop working for safety.

Central heating flow NTC fault

What causes this fault?

This fault occurs when the internal sensor responsible for monitoring the heat of the water leaving the boiler fails or sends an incorrect signal. The most common reason is that the sensor has physically degraded over time or developed an electrical short, meaning the boiler can no longer safely regulate its temperature. In some cases, it may be caused by loose or damaged wiring connecting the sensor to the main control board.