Jandy Flue Sensor Kit Thermistor For JXiQ Heater | R0719402OEM Jandy JXiQ Heater Flue Sensor Kit R0719402 is a factory authorized replacement part engineered for JXiQ heater models 200, 260, and 400. This precision thermistor monitors flue gas temperatures inside the exhaust path to help prevent overheating and ensure safe operation. When unsafe conditions arise, it signals the control system to trigger an automatic shutdown, protecting the heater from potential damage. Built to Jandys strict quality