{"product_id":"oem-lennox-limit-switch-36w90","title":"OEM Lennox Limit Switch — 36W90","description":"\u003cp\u003eThe genuine OEM Lennox \u003cstrong\u003e36W90\u003c\/strong\u003e limit switch is a critical safety control that monitors the temperature inside your Lennox furnace's heat exchanger and plenum. If temperatures rise beyond a safe threshold, the switch shuts off the burners to prevent overheating, protecting the heat exchanger and reducing the risk of a fire or cracked exchanger.\u003c\/p\u003e\u003cp\u003eA faulty limit switch commonly causes short-cycling, where the furnace repeatedly starts and stops, or a blower that runs continuously. In other cases the furnace may fail to fire at all, or shut down on a limit fault, leaving you without heat. Restricted airflow from a dirty filter or blower issue can also trip a functioning switch — but a worn switch will fail even under normal conditions.\u003c\/p\u003e\u003cp\u003eThe OEM \u003cstrong\u003e36W90\u003c\/strong\u003e is calibrated to the exact open and close temperatures Lennox specified for your model. A generic switch with a different trip point can allow dangerous overheating or cause nuisance shutdowns. This factory replacement restores proper high-limit protection and guarantees correct fit and calibration for your Lennox furnace.\u003c\/p\u003e","brand":"Lennox","offers":[{"title":"Default Title","offer_id":63081107751283,"sku":"LNX-36W90","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-36W90.jpg?v=1783762533","url":"https:\/\/nationalhvacparts.com\/products\/oem-lennox-limit-switch-36w90","provider":"National HVAC Parts","version":"1.0","type":"link"}