{"product_id":"oem-lennox-limit-switch-18k80","title":"OEM Lennox Limit Switch — 18K80","description":"\u003cp\u003eThe genuine OEM Lennox \u003cstrong\u003e18K80\u003c\/strong\u003e limit switch is a high-temperature safety control that protects your Lennox furnace from overheating. Mounted near the heat exchanger, it continuously senses supply-air temperature and shuts off the burners if the furnace exceeds a safe threshold — typically caused by restricted airflow. As a direct factory replacement, the \u003cstrong\u003e18K80\u003c\/strong\u003e opens and resets at the precise temperatures specified for your Lennox model.\u003c\/p\u003e\u003ch3\u003eCommon Failure Symptoms\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eFurnace short-cycles, firing then shutting off on high limit\u003c\/li\u003e\n\u003cli\u003eBlower runs continuously while burners stay off\u003c\/li\u003e\n\u003cli\u003eNo heat with a limit-related fault code\u003c\/li\u003e\n\u003cli\u003eOverheating due to a switch that fails to reset properly\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eA tripped or failed limit switch is a common no-heat complaint and an important indicator of airflow problems such as a clogged filter or blocked ductwork.\u003c\/p\u003e\u003ch3\u003eWhy OEM Matters\u003c\/h3\u003e\u003cp\u003eBecause a limit switch is a primary safety device, correct trip and reset temperatures are essential. Generic switches with the wrong ratings can nuisance-trip or fail to protect the heat exchanger. The OEM Lennox \u003cstrong\u003e18K80\u003c\/strong\u003e is calibrated to factory specifications, ensuring exact fit, dependable overheat protection, and safe operation of your Lennox equipment.\u003c\/p\u003e","brand":"Lennox","offers":[{"title":"Default Title","offer_id":63081113878899,"sku":"LNX-18K80","price":19.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-limit-switch-snap-disc-LNX-18K80.jpg?v=1783762472","url":"https:\/\/nationalhvacparts.com\/products\/oem-lennox-limit-switch-18k80","provider":"National HVAC Parts","version":"1.0","type":"link"}