{"product_id":"icp-defrost-control-board-for-wph4364000rkb1-oem-circuit-board-ships-today","title":"ICP Defrost Control Board for WPH4364000RKB1 — OEM Circuit Board | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThis genuine OEM circuit \/ defrost control board (OEM part number 1178001) is the brain of the outdoor unit on the ICP \/ Tempstar \/ Heil WPH4364000RKB1 heat pump. It manages the defrost cycle, compressor and fan sequencing, reversing valve switching, and time\/temperature defrost logic. When this board fails, the heat pump may stop defrosting (icing over in winter), fail to switch between heating and cooling, short-cycle, or stop running entirely. Installing the correct OEM board restores proper outdoor control and protects the compressor from icing and improper sequencing.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpec\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eOEM Part Number\u003c\/td\u003e\n\u003ctd\u003e1178001\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eDefrost \/ Outdoor Control Board\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eICP \/ Tempstar \/ Heil\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eControl Voltage\u003c\/td\u003e\n\u003ctd\u003e24V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFunction\u003c\/td\u003e\n\u003ctd\u003eDefrost timing, compressor \u0026amp; fan sequencing, reversing valve control\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cp\u003eBuilt as a direct factory replacement for the ICP \/ Tempstar \/ Heil WPH4364000RKB1 heat pump. It also fits related ICP-family heat pumps that shipped with this defrost control board. Verify the board's part number, connector layout, and terminal designations against your existing board before installing.\u003c\/p\u003e\u003ch3\u003eInstallation Guide\u003c\/h3\u003e\u003col\u003e\n\u003cli\u003e\n\u003cstrong\u003eSafety First\u003c\/strong\u003e — Disconnect power at the disconnect and breaker, then verify zero voltage with a multimeter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the electrical\/control access panel on the outdoor unit.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph every connector, plug, and the defrost timer\/jumper settings before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Unplug the harnesses, release the board standoffs\/screws, and lift out the old board.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new board, transfer the defrost timer\/jumper setting, and reconnect every harness per your photo.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and confirm proper startup, defrost initiation, and heating\/cooling changeover.\u003c\/li\u003e\n\u003c\/ol\u003e\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eOutdoor coil ices over and the unit never goes into defrost.\u003c\/li\u003e\n\u003cli\u003eHeat pump won't switch between heating and cooling modes.\u003c\/li\u003e\n\u003cli\u003eCompressor or fan short-cycles or won't start at all.\u003c\/li\u003e\n\u003cli\u003eNo control voltage output to the contactor or reversing valve.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eShipping \u0026amp; Returns\u003c\/h3\u003e\u003cp\u003eShips same day on orders placed before 3 PM CST. 30-day returns on unused parts. Backed by the National HVAC Parts fitment guarantee.\u003c\/p\u003e","brand":"ICP","offers":[{"title":"OEM","offer_id":63021485850995,"sku":"WPH4364000RKB1","price":219.7,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":63047496597875,"sku":"WPH4364000RKB1-GEN","price":169.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-control-board-defrost-WPH4364000RKB1.jpg?v=1782886601","url":"https:\/\/nationalhvacparts.com\/products\/icp-defrost-control-board-for-wph4364000rkb1-oem-circuit-board-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}