{"product_id":"oem-lennox-defrost-control-board-18m23","title":"OEM Lennox Defrost Control Board — 18M23","description":"\u003cp\u003eThe genuine OEM Lennox \u003cstrong\u003e18M23\u003c\/strong\u003e defrost control board is the electronic brain that manages the defrost cycle on your Lennox heat pump. It monitors coil temperature and run time, then reverses the system to melt frost and ice from the outdoor coil so efficient heating can continue in cold weather. As a direct factory replacement, the \u003cstrong\u003e18M23\u003c\/strong\u003e restores precise defrost timing and reliable system sequencing to your Lennox unit.\u003c\/p\u003e\u003ch3\u003eCommon Failure Symptoms\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eOutdoor coil ices over and never clears\u003c\/li\u003e\n\u003cli\u003eHeat pump fails to switch into or out of defrost\u003c\/li\u003e\n\u003cli\u003eAuxiliary\/emergency heat runs constantly\u003c\/li\u003e\n\u003cli\u003eErratic operation, no outdoor unit response, or blank diagnostics\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eA failed defrost board often shows up as reduced heating capacity, excessive ice buildup, or a spike in electric bills from constant strip-heat operation.\u003c\/p\u003e\u003ch3\u003eWhy OEM Matters\u003c\/h3\u003e\u003cp\u003eDefrost boards are programmed to model-specific timing and sensor logic. Universal or aftermarket boards can misread defrost intervals, causing icing or wasted energy. The OEM Lennox \u003cstrong\u003e18M23\u003c\/strong\u003e is built to your system's exact control specifications, guaranteeing correct terminal layout, dependable defrost management, and proper integration with your Lennox equipment.\u003c\/p\u003e","brand":"Lennox","offers":[{"title":"Default Title","offer_id":63081113813363,"sku":"LNX-18M23","price":129.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-control-board-defrost-LNX-18M23.jpg?v=1783760053","url":"https:\/\/nationalhvacparts.com\/products\/oem-lennox-defrost-control-board-18m23","provider":"National HVAC Parts","version":"1.0","type":"link"}