{"product_id":"oem-lennox-limit-switch-10m63","title":"OEM Lennox Limit Switch — 10M63","description":"\u003cp\u003eThe genuine OEM Lennox \u003cstrong\u003e10M63\u003c\/strong\u003e limit switch is a temperature-activated safety control mounted on the heat exchanger or plenum of your Lennox furnace. It continuously monitors supply-air temperature and shuts off the gas valve if the furnace overheats — protecting the heat exchanger from cracking and preventing a fire hazard when airflow is restricted.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCommon failure symptoms:\u003c\/strong\u003e Furnace short-cycling on the high limit, the burner shutting off while the blower keeps running, no heat with a limit-related fault code, or a furnace that trips off shortly after ignition. A dirty filter, blocked ductwork, or a failing blower often stresses the switch until it opens prematurely or fails outright.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy OEM matters:\u003c\/strong\u003e Limit switches are calibrated to open and close at temperature setpoints specific to your Lennox heat exchanger design. The factory \u003cstrong\u003e10M63\u003c\/strong\u003e is set to those exact trip points, ensuring the furnace shuts down at a safe threshold — not too early to cause nuisance trips, not too late to risk damage. Generic switches with the wrong rating compromise this critical safety function. Always replace with genuine Lennox.\u003c\/p\u003e","brand":"Lennox","offers":[{"title":"Default Title","offer_id":63081144942963,"sku":"LNX-10M63","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-10M63.jpg?v=1783762447","url":"https:\/\/nationalhvacparts.com\/products\/oem-lennox-limit-switch-10m63","provider":"National HVAC Parts","version":"1.0","type":"link"}