{"product_id":"oem-lennox-furnace-limit-switch-73k19","title":"OEM Lennox Furnace Limit Switch — 73K19","description":"\u003cp\u003eThe genuine OEM Lennox \u003cstrong\u003e73K19\u003c\/strong\u003e is a high-limit safety switch that safeguards your Lennox furnace by monitoring heat exchanger temperature during every heating cycle. Should the temperature exceed the switch's rated threshold, the \u003cstrong\u003e73K19\u003c\/strong\u003e immediately opens the circuit to the burners or gas valve, halting combustion until the system cools to a safe level. This automatic-reset control is an essential safety device found across many Lennox gas furnace and air handler platforms.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCommon failure symptoms:\u003c\/strong\u003e A worn or defective limit switch commonly results in short cycling, no heat on demand, a continuously running blower, or a limit-open error at the furnace control board. Years of heat exposure can degrade the bimetal element, causing premature tripping or a failure to open when it should.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy OEM matters:\u003c\/strong\u003e Every \u003cstrong\u003e73K19\u003c\/strong\u003e is factory-calibrated to a precise trip and reset temperature matched to your Lennox model. A generic replacement with the wrong rating can undermine safety or trigger false shutdowns. The OEM \u003cstrong\u003e73K19\u003c\/strong\u003e delivers exact calibration, a correct mounting footprint, and factory-grade reliability for lasting protection.\u003c\/p\u003e","brand":"Lennox","offers":[{"title":"Default Title","offer_id":63081096348019,"sku":"LNX-73K19","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-73K19.jpg?v=1783761156","url":"https:\/\/nationalhvacparts.com\/products\/oem-lennox-furnace-limit-switch-73k19","provider":"National HVAC Parts","version":"1.0","type":"link"}