{"product_id":"oem-lennox-furnace-limit-switch-73k18","title":"OEM Lennox Furnace Limit Switch — 73K18","description":"\u003cp\u003eThe genuine OEM Lennox \u003cstrong\u003e73K18\u003c\/strong\u003e is a furnace high-limit safety switch engineered to protect your Lennox heating system from overheating. It senses the temperature near the heat exchanger and, if it climbs past the factory-set trip point, the \u003cstrong\u003e73K18\u003c\/strong\u003e disconnects power to the burners or gas valve to shut down the heat cycle, resetting automatically once temperatures normalize. This protective control appears on numerous Lennox gas furnaces and air handling units.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCommon failure symptoms:\u003c\/strong\u003e Typical signs of a failing limit switch include short cycling, intermittent or no heat, a blower motor that runs nonstop, and limit-fault lockouts at the furnace control. Prolonged thermal cycling can cause the internal contacts to stick or the trip temperature to drift out of specification.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy OEM matters:\u003c\/strong\u003e The \u003cstrong\u003e73K18\u003c\/strong\u003e is calibrated to a model-specific trip and reset temperature, so a mismatched substitute can jeopardize safety or cause nuisance shutdowns. Installing the OEM \u003cstrong\u003e73K18\u003c\/strong\u003e ensures the precise calibration, terminal layout, and secure fit your Lennox furnace requires for safe, consistent heating.\u003c\/p\u003e","brand":"Lennox","offers":[{"title":"Default Title","offer_id":63081096380787,"sku":"LNX-73K18","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-73K18.jpg?v=1783761154","url":"https:\/\/nationalhvacparts.com\/products\/oem-lennox-furnace-limit-switch-73k18","provider":"National HVAC Parts","version":"1.0","type":"link"}