Genuine Daikin 1701731 Liquid Thermistor is the liquid-line temperature sensor that gives the unit the reading it uses to run correctly through the cycle. When it starts to fail, the unit may lose output, run hot or cold, or stop and start at odd times. A genuine sensor reads temperature the way your Daikin expects, keeping the unit accurate — where a non-genuine part can read off and leave it running incorrectly.