Genuine Hayward Replacement Temperature Sensor, Thermistor for Hayward FD Heaters. Please check Owners Manual to determine if you require FDXLTER1930 or FDXLTER1931. This specific thermistor temperature sensor is for units made in 2019 and before. If your pool heater was built in 2012 and forward, you require FDXLTER1931.
All service on gas appliances shall be performed by a licensed HVAC contractor