{"product_id":"oem-lennox-pressure-switch-57m67","title":"OEM Lennox Pressure Switch — 57M67","description":"\u003cp\u003eThe genuine OEM Lennox \u003cstrong\u003e57M67\u003c\/strong\u003e pressure switch is a critical safety control that monitors venting airflow in your Lennox furnace. It confirms that the draft inducer is drawing combustion gases properly before the control board allows the gas valve to open and the burners to ignite. This ensures your furnace only fires when it can safely exhaust flue gases, protecting your home from carbon monoxide risk.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCommon failure symptoms\u003c\/strong\u003e include a furnace that ignites and then shuts off, repeated short cycling, a blower that runs without heat, or a control board flashing a pressure switch fault code. Blocked vent pipes, a cracked hose, or a fatigued diaphragm inside the switch are frequent culprits. When the \u003cstrong\u003e57M67\u003c\/strong\u003e can no longer close reliably on the correct pressure setpoint, the furnace locks out to stay safe.\u003c\/p\u003e\u003cp\u003eChoosing an OEM Lennox part matters because pressure switches are calibrated to a specific trip point measured in inches of water column. A generic switch with the wrong setpoint can allow unsafe operation or cause nuisance lockouts. The \u003cstrong\u003e57M67\u003c\/strong\u003e is factory-matched to Lennox specifications for a direct, reliable fit and correct performance in the systems it was engineered for.\u003c\/p\u003e","brand":"Lennox","offers":[{"title":"Default Title","offer_id":63081102049651,"sku":"LNX-57M67","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-57M67.jpg?v=1783763058","url":"https:\/\/nationalhvacparts.com\/products\/oem-lennox-pressure-switch-57m67","provider":"National HVAC Parts","version":"1.0","type":"link"}