{"product_id":"oem-lennox-limit-switch-57w38","title":"OEM Lennox Limit Switch — 57W38","description":"\u003cp\u003eThe genuine OEM Lennox \u003cstrong\u003e57W38\u003c\/strong\u003e limit switch is a temperature-sensing safety control mounted in the heat-exchanger airflow path of Lennox gas furnaces. It protects the system from overheating by cutting power to the gas valve whenever supply-air temperature climbs above its rated set point — typically caused by restricted airflow from a dirty filter, a failing blower motor, or closed registers. Once temperatures return to normal the switch resets and allows the furnace to fire again.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCommon failure symptoms:\u003c\/strong\u003e Short-cycling on heat, the burners igniting then dropping out repeatedly, no heat with the blower still running, or a limit\/overheat code on the control board. A limit switch that has drifted out of calibration or failed open will keep the furnace from staying lit.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy OEM matters:\u003c\/strong\u003e The Lennox \u003cstrong\u003e57W38\u003c\/strong\u003e is matched to the precise trip and reset temperatures your furnace was designed for. An off-spec aftermarket switch can nuisance-trip or fail to open when it should, risking heat-exchanger damage. Choosing the factory part guarantees correct fit and reliable overheat protection for your Lennox equipment.\u003c\/p\u003e","brand":"Lennox","offers":[{"title":"Default Title","offer_id":63081101099379,"sku":"LNX-57W38","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-57W38.jpg?v=1783762584","url":"https:\/\/nationalhvacparts.com\/products\/oem-lennox-limit-switch-57w38","provider":"National HVAC Parts","version":"1.0","type":"link"}