Genuine Daikin 008792J Indoor Air Thermistor is the sensor that reads the temperature of the air entering the indoor unit, so it can judge the room and run to suit. When it begins to fail, the unit may stop holding the set temperature, run warmer or cooler than the room needs, or switch on and off at the wrong times. A genuine sensor reads the air the way your Daikin expects, keeping it accurate — where a non-genuine part can read off and leave it running wrong.