{"product_id":"oem-lennox-primary-gas-furnace-heat-exchanger-92l74","title":"OEM Lennox Primary Gas Furnace Heat Exchanger — 92L74","description":"\u003cp\u003eThe genuine OEM Lennox \u003cstrong\u003e92L74\u003c\/strong\u003e (interchange 20281803) is the primary gas furnace heat exchanger, the core component that separates combustion gases from the air circulated through your home. As burner flames heat the exchanger walls, the blower moves conditioned air across the exterior, delivering warmth while safely venting exhaust up the flue. A properly functioning primary heat exchanger is essential to both the efficiency and the safety of your Lennox gas furnace.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCommon failure symptoms:\u003c\/strong\u003e Watch for visible cracks or rust on the exchanger surface, a flickering or rolling burner flame, soot buildup, unusual odors, a repeatedly tripping flame sensor or limit switch, and — most seriously — carbon monoxide detector activation. A cracked heat exchanger can leak combustion byproducts into the airstream and must be replaced promptly.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy OEM matters:\u003c\/strong\u003e The \u003cstrong\u003e92L74\u003c\/strong\u003e is engineered to Lennox's exact metallurgy, tube geometry, and thermal tolerances. Aftermarket substitutes can warp, crack prematurely, or fit poorly, compromising combustion safety and voiding warranties. Installing the factory-specified part restores rated AFUE efficiency and ensures a correct, safe fit in your Lennox furnace.\u003c\/p\u003e","brand":"Lennox","offers":[{"title":"Default Title","offer_id":63081064890739,"sku":"LNX-92L74","price":399.95,"currency_code":"USD","in_stock":true}],"url":"https:\/\/nationalhvacparts.com\/products\/oem-lennox-primary-gas-furnace-heat-exchanger-92l74","provider":"National HVAC Parts","version":"1.0","type":"link"}