{"product_id":"oem-lennox-scr-control-board-75a-3-phase-87w66","title":"OEM Lennox SCR Control Board 75A 3-Phase — 87W66","description":"\u003cp\u003eThe genuine OEM Lennox \u003cstrong\u003e87W66\u003c\/strong\u003e (factory part 103324-08) is a 75-amp, three-phase SCR (silicon-controlled rectifier) control board used to modulate electric resistance heat in compatible Lennox rooftop and packaged units. By electronically switching power to the heating elements, it delivers smooth, staged heat, tighter supply-air temperature control, and reduced wear compared to mechanical contactor staging.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCommon failure symptoms:\u003c\/strong\u003e When this SCR control fails you may see heat that will not energize or will not shut off, elements cycling erratically, tripped high-limit switches, or inconsistent discharge-air temperatures. Nuisance breaker trips, a burnt-electronics odor, visible scorching, or fault codes at the unit controller indicate the board should be replaced.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy OEM matters:\u003c\/strong\u003e Lennox manufactures the \u003cstrong\u003e87W66\u003c\/strong\u003e to precise 75-amp, three-phase amperage, phase, and control-signal specifications for their equipment. A genuine OEM board ensures correct gate triggering, thermal ratings, and connector fitment — safeguarding your heating elements and unit control against the mismatched timing and early failures typical of generic parts. Installing OEM keeps your system within factory specifications and helps maintain warranty coverage.\u003c\/p\u003e","brand":"Lennox","offers":[{"title":"Default Title","offer_id":63081079046515,"sku":"LNX-87W66","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-87W66.jpg?v=1783763489","url":"https:\/\/nationalhvacparts.com\/products\/oem-lennox-scr-control-board-75a-3-phase-87w66","provider":"National HVAC Parts","version":"1.0","type":"link"}