{"product_id":"oem-lennox-flame-sensor-19d31","title":"OEM Lennox Flame Sensor — 19D31","description":"\u003cp\u003eThe genuine OEM Lennox \u003cstrong\u003e19D31\u003c\/strong\u003e flame sensor is a critical safety component in your gas furnace. It uses flame rectification to confirm that the burner has actually lit, signaling the control board to keep the gas valve open only when a real flame is present. This protects your Lennox equipment and home by preventing raw gas from flowing when ignition fails.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCommon failure symptoms:\u003c\/strong\u003e When the \u003cstrong\u003e19D31\u003c\/strong\u003e sensor becomes dirty, corroded, or worn, your furnace will typically light briefly and then shut down after a few seconds — a condition known as short cycling. You may also experience repeated ignition lockouts, no heat on demand, or the blower running without producing warm air.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy OEM matters:\u003c\/strong\u003e Lennox furnace control boards are calibrated to expect a precise microamp signal from the flame sensor. Aftermarket sensors often fall outside this range, causing nuisance faults, unreliable ignition, and premature lockouts. The OEM \u003cstrong\u003e19D31\u003c\/strong\u003e guarantees the correct rod length, mounting geometry, and signal characteristics for a direct fit and dependable operation season after season.\u003c\/p\u003e","brand":"Lennox","offers":[{"title":"Default Title","offer_id":63081132228979,"sku":"LNX-19D31","price":19.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-flame-sensor-straight-LNX-19D31.jpg?v=1783761014","url":"https:\/\/nationalhvacparts.com\/products\/oem-lennox-flame-sensor-19d31","provider":"National HVAC Parts","version":"1.0","type":"link"}