{"product_id":"oem-lennox-limit-switch-38m69","title":"OEM Lennox Limit Switch — 38M69","description":"\u003cp\u003eThe genuine OEM Lennox \u003cstrong\u003e38M69\u003c\/strong\u003e limit switch is a temperature-sensing safety control mounted near the heat exchanger of your Lennox furnace. It monitors plenum and heat exchanger temperatures and opens the circuit to shut off the burners if the unit overheats — a condition usually caused by restricted airflow, a dirty filter, a failing blower motor, or a blocked duct. This prevents heat exchanger cracking and dangerous overheating.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCommon failure symptoms:\u003c\/strong\u003e The furnace short-cycles on heat, the burners ignite and then shut off after a few minutes, you get no heat at all, or the blower runs continuously. A limit switch that fails open locks out heating, while one that fails closed removes essential overheat protection.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy OEM matters:\u003c\/strong\u003e The Lennox \u003cstrong\u003e38M69\u003c\/strong\u003e is calibrated to the exact open and close temperatures specified for your furnace model. A generic limit with the wrong temperature rating can allow unsafe overheating or trigger constant nuisance shutdowns. The factory part guarantees correct calibration, proper terminal fit, and reliable safe operation — protecting both your equipment and your home.\u003c\/p\u003e","brand":"Lennox","offers":[{"title":"Default Title","offer_id":63081107423603,"sku":"LNX-38M69","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-38M69.jpg?v=1783762543","url":"https:\/\/nationalhvacparts.com\/products\/oem-lennox-limit-switch-38m69","provider":"National HVAC Parts","version":"1.0","type":"link"}