{"product_id":"oem-lennox-pressure-switch-w-bracket-51w93","title":"OEM Lennox Pressure Switch w\/ Bracket — 51W93","description":"\u003cp\u003eThe Lennox \u003cstrong\u003e51W93\u003c\/strong\u003e pressure switch, supplied complete with its mounting bracket, verifies proper combustion airflow and venting in your Lennox furnace before allowing ignition. As the inducer motor spins up, it creates a negative pressure that the \u003cstrong\u003e51W93\u003c\/strong\u003e senses through its port tubing. Only when adequate draft is confirmed does the switch close and permit the ignition sequence to proceed — protecting against dangerous flue blockages and improper venting.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCommon failure symptoms:\u003c\/strong\u003e When this switch fails, the furnace inducer will run but the burners never light, and the control board typically flashes a pressure-switch or open-circuit fault. You may experience short-cycling, repeated lockouts, or a furnace that starts only intermittently. Cracked tubing, a stuck diaphragm, or a switch out of calibration are the usual culprits.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy OEM matters:\u003c\/strong\u003e The \u003cstrong\u003e51W93\u003c\/strong\u003e is set to the exact water-column pressure your Lennox furnace requires, and the included bracket ensures correct positioning and tubing routing. Aftermarket switches with the wrong set point can prevent ignition or bypass a genuine venting problem. The genuine OEM assembly guarantees precise calibration, proper fit, and full compatibility with your Lennox equipment.\u003c\/p\u003e","brand":"Lennox","offers":[{"title":"Default Title","offer_id":63081103622515,"sku":"LNX-51W93","price":24.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-pressure-switch-single-LNX-51W93.jpg?v=1783762947","url":"https:\/\/nationalhvacparts.com\/products\/oem-lennox-pressure-switch-w-bracket-51w93","provider":"National HVAC Parts","version":"1.0","type":"link"}