{"product_id":"oem-lennox-flame-sensor-12l09","title":"OEM Lennox Flame Sensor — 12L09","description":"\u003cp\u003eThe genuine OEM Lennox \u003cstrong\u003e12L09\u003c\/strong\u003e flame sensor confirms that your gas furnace's burner has ignited, allowing the control board to keep the gas valve open only while a true flame is present. Using flame rectification, the sensor rod conducts a small microamp current through the flame back to the board, providing the proof-of-flame signal that keeps your Lennox heating system running safely.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCommon failure symptoms:\u003c\/strong\u003e A dirty, corroded, or failing \u003cstrong\u003e12L09\u003c\/strong\u003e sensor typically causes the furnace to light and then shut off after a few seconds, short cycling, repeated ignition lockouts, and periods of no heat. If cleaning the rod only restores heat temporarily, the sensor has degraded and should be replaced.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy OEM matters:\u003c\/strong\u003e Lennox furnace controls expect a precise flame-sense current, and an out-of-spec aftermarket sensor can trigger nuisance faults and unreliable ignition. The OEM \u003cstrong\u003e12L09\u003c\/strong\u003e delivers the exact rod length, mounting bracket, and signal response your board is designed for, ensuring a direct fit and consistent, worry-free performance.\u003c\/p\u003e","brand":"Lennox","offers":[{"title":"Default Title","offer_id":63081132360051,"sku":"LNX-12L09","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-12L09.jpg?v=1783761008","url":"https:\/\/nationalhvacparts.com\/products\/oem-lennox-flame-sensor-12l09","provider":"National HVAC Parts","version":"1.0","type":"link"}