{"product_id":"oem-lennox-gp3-controller-13j79","title":"OEM Lennox GP3 Controller — 13J79","description":"\u003cp\u003eThe Lennox \u003cstrong\u003e13J79\u003c\/strong\u003e (part 104490-01) GP3 controller is a genuine OEM control board that governs the operating logic of your Lennox equipment, sequencing components, monitoring safety inputs, and coordinating staging so the system responds correctly to thermostat demand. As the central circuit board, it processes sensor feedback and drives the relays and outputs that keep the unit running safely and efficiently.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCommon failure symptoms:\u003c\/strong\u003e the system not starting on a call, erratic or short cycling, blower or stages failing to energize, fault or diagnostic LED codes, no response to the thermostat, or a control that has no output despite proper incoming power. Board failures frequently follow power surges, moisture intrusion, or aging solder joints and relays.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy OEM matters:\u003c\/strong\u003e the GP3 controller is programmed with Lennox-specific firmware, timing, and safety logic matched to your exact model. The factory \u003cstrong\u003e13J79\u003c\/strong\u003e ensures correct relay ratings, terminal layout, and control sequences — aftermarket or reflashed boards can misfire equipment or bypass built-in protections. Replacing with the genuine OEM controller restores dependable, factory-rated operation of your Lennox system.\u003c\/p\u003e","brand":"Lennox","offers":[{"title":"Default Title","offer_id":63081078915443,"sku":"LNX-13J79","price":39.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-control-board-furnace-LNX-13J79.jpg?v=1783761332","url":"https:\/\/nationalhvacparts.com\/products\/oem-lennox-gp3-controller-13j79","provider":"National HVAC Parts","version":"1.0","type":"link"}