What is NTC Sensor?

NTC sensor is a temperature sensor that measures the temperature in combi boilers.

It works with negative heat coefficient. As the temperature increases, the ohm resistance increases upwards. Various types of water-contact and non-water-contact NTC sensors are used in combi boilers. Both have the same task.

The NTC, PTC faults of the boilers are usually caused by a short circuit. Water leakage and oxidation and NTC sensor short circuit are among the most common failures.

If the sensor, which is easy to change, is immersion, it is replaced with a new one after the water inside the device is drained from the drain valve.

Many devices have more than one NTC. In general, there are 2 units, and heating and hot water are also used.

Some rare brands can use more than 2 sensors, and in advanced devices that provide better comfort, we can see that two NTCs are used for heating flow and return, and 3 NTC for hot water flow.

These parts vary according to boiler brands and are used according to their electronic software. In case of NTC failure, the device does not ignite at all.

For example, when there is a hot water NTC failure, the device does not fire in hot water mode. However, since the NTC of the heating system is different, it does not affect the hot water position and works.