{"product_id":"fujitsu-k9900878009-middle-heat-thermistor","title":"Fujitsu k9900878009 Middle Heat Thermistor","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\u003cp\u003eThe FUJITSU k9900878009 is a middle heat thermistor designed for use in Fujitsu mini-split outdoor units. This temperature sensor monitors heat exchanger coil temperature at a mid-point location, providing feedback to the system control board to regulate compressor and fan operation. It is a direct OEM replacement part installed by licensed HVAC technicians servicing Fujitsu ductless systems. Proper thermistor function is critical to system efficiency, defrost cycle accuracy, and protection against compressor overload conditions.\u003c\/p\u003e\u003cp\u003eThis thermistor is used in Fujitsu outdoor condensing units in residential and light-commercial ductless mini-split applications. It mounts to the middle section of the heat exchanger and feeds temperature data to the main control board. Compatible outdoor unit models include AOU18RLXFZH, AOU24RLXFZH, and AOU36RLXFZ1. Replacement is typically required when the system throws a thermistor fault code or exhibits erratic defrost or heating performance.\u003c\/p\u003e\u003ch4\u003eKey Features\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003eOEM replacement thermistor for Fujitsu outdoor mini-split units\u003c\/li\u003e\n\u003cli\u003eMonitors mid-coil heat exchanger temperature for system control and protection\u003c\/li\u003e\n\u003cli\u003eSupports accurate defrost cycle initiation and termination\u003c\/li\u003e\n\u003cli\u003eDirect fit for specified AOU-series outdoor unit models\u003c\/li\u003e\n\u003cli\u003eCompact form factor for straightforward swap-out replacement\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eCompatibility\u003c\/h4\u003e\u003cp\u003eCompatible with Fujitsu outdoor units AOU18RLXFZH, AOU24RLXFZH, and AOU36RLXFZ1.\u003c\/p\u003e\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\u003cp\u003eInstallation should be performed by a licensed HVAC technician familiar with ductless mini-split systems. Disconnect power to the outdoor unit at the disconnect box before removing or installing any sensors. Ensure the thermistor connector is fully seated and the lead wire is routed away from sharp edges or moving components. Consult the unit wiring diagram and service manual for connector location and fault code diagnostics.\u003c\/p\u003e\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eShipping Length\u003c\/strong\u003e: 1.123 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShipping Width\u003c\/strong\u003e: 4 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShipping Height\u003c\/strong\u003e: 4 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShipping Weight\u003c\/strong\u003e: 1.123 pounds\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eStandard Information\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand\u003c\/strong\u003e: FUJITSU\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: k9900878009\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"FUJITSU","offers":[{"title":"Default Title","offer_id":51619921527090,"sku":"K9900878009","price":17.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/a04c887921c84e3488052df740445315.jpg?v=1787337344","url":"https:\/\/voomisupply.com\/products\/fujitsu-k9900878009-middle-heat-thermistor","provider":"Voomi Supply","version":"1.0","type":"link"}