{"product_id":"oem-lennox-limit-switch-36k29","title":"OEM Lennox Limit Switch — 36K29","description":"\u003cp\u003eThe genuine OEM Lennox \u003cstrong\u003e36K29\u003c\/strong\u003e limit switch is a thermally activated safety device that guards your furnace against dangerous overheating. Positioned to sense heat exchanger or plenum temperature, it interrupts the gas valve circuit whenever the supply air rises above the factory-set safe limit, most often due to blocked filters, closed registers, or a weak blower motor. It is a key line of defense for your Lennox heating system.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCommon failure symptoms:\u003c\/strong\u003e When the \u003cstrong\u003e36K29\u003c\/strong\u003e degrades it may open too early, producing short cycling and inconsistent heat, or stick open and block ignition entirely. Watch for the blower running without heat, repeated lockouts, or a high-limit fault indicated on the control board.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy OEM matters:\u003c\/strong\u003e Each Lennox limit switch is set to a model-specific trip point. Installing an aftermarket switch with the wrong calibration invites nuisance trips or leaves the heat exchanger unprotected. The OEM Lennox \u003cstrong\u003e36K29\u003c\/strong\u003e delivers the exact rating and mounting your furnace was designed for.\u003c\/p\u003e","brand":"Lennox","offers":[{"title":"Default Title","offer_id":63081108013427,"sku":"LNX-36K29","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-36K29.jpg?v=1783762526","url":"https:\/\/nationalhvacparts.com\/products\/oem-lennox-limit-switch-36k29","provider":"National HVAC Parts","version":"1.0","type":"link"}