{"product_id":"oem-lennox-limit-switch-73w19","title":"OEM Lennox Limit Switch — 73W19","description":"\u003cp\u003eThe genuine OEM Lennox \u003cstrong\u003e73W19\u003c\/strong\u003e limit switch is a temperature-activated safety control that protects your furnace from overheating. Mounted on or near the heat exchanger, it continuously monitors plenum temperature and interrupts the burner circuit if heat rises above a safe threshold — typically when airflow is restricted. This exact-fit component is engineered to the precise trip and reset temperatures your Lennox furnace was designed around.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCommon failure symptoms\u003c\/strong\u003e include short cycling on the burners, the furnace shutting down mid-cycle, blowing cool air, or the unit failing to fire at all. A limit switch that trips prematurely or fails open is a frequent culprit behind intermittent no-heat calls, especially when paired with a dirty filter or blocked ductwork.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy OEM matters:\u003c\/strong\u003e aftermarket limit switches often use different trip points and mounting geometry, which can compromise the safety function your Lennox system relies on. Installing the factory-specified \u003cstrong\u003e73W19\u003c\/strong\u003e ensures the correct temperature calibration, proper fit, and reliable protection of your heat exchanger — safeguarding both performance and warranty coverage.\u003c\/p\u003e","brand":"Lennox","offers":[{"title":"Default Title","offer_id":63081096085875,"sku":"LNX-73W19","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-73W19.jpg?v=1783762601","url":"https:\/\/nationalhvacparts.com\/products\/oem-lennox-limit-switch-73w19","provider":"National HVAC Parts","version":"1.0","type":"link"}