{"product_id":"oem-lennox-furnace-limit-switch-73k20","title":"OEM Lennox Furnace Limit Switch — 73K20","description":"\u003cp\u003eThe genuine OEM Lennox \u003cstrong\u003e73K20\u003c\/strong\u003e is a furnace high-limit safety switch that continuously monitors heat exchanger and plenum temperature to keep your Lennox equipment operating within safe limits. If temperatures rise above the switch's factory-rated setpoint, the \u003cstrong\u003e73K20\u003c\/strong\u003e cuts power to the burners or gas valve to stop the heating cycle, then automatically resets once the furnace cools. It is a key protective control on a wide range of Lennox gas furnaces and air handlers.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCommon failure symptoms:\u003c\/strong\u003e When this limit switch fails, you may experience short cycling, complete loss of heat, a blower that won't shut off, or a control board reporting a limit lockout. Repeated thermal stress can cause the contacts to stick or the trip point to drift, leading to unreliable or unsafe operation.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy OEM matters:\u003c\/strong\u003e The \u003cstrong\u003e73K20\u003c\/strong\u003e is temperature-calibrated for specific Lennox models, and an incorrect trip rating can compromise both comfort and safety. Choosing the OEM \u003cstrong\u003e73K20\u003c\/strong\u003e guarantees the exact calibration, terminal configuration, and mounting your furnace was engineered for — restoring dependable, code-compliant heating performance.\u003c\/p\u003e","brand":"Lennox","offers":[{"title":"Default Title","offer_id":63081096315251,"sku":"LNX-73K20","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-73K20.jpg?v=1783761157","url":"https:\/\/nationalhvacparts.com\/products\/oem-lennox-furnace-limit-switch-73k20","provider":"National HVAC Parts","version":"1.0","type":"link"}