{"product_id":"icp-control-board-for-wph4484000rka1-defrost-circuit-board-ships-today","title":"ICP Control Board for WPH4484000RKA1 — Defrost Circuit Board | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\n\u003cp\u003eThis genuine OEM circuit board (part number 1178001) is the factory replacement control board for the ICP \/ Tempstar \/ Heil WPH4484000RKA1 heat pump. On a heat-pump condensing unit this board manages the defrost cycle, sequences the compressor and reversing valve, and coordinates the 24V control signals between the thermostat and the outdoor components. It monitors the defrost timer and coil temperature, switching the unit into and out of defrost so the outdoor coil sheds frost in heating mode. A failed control board causes erratic operation — no compressor, a unit stuck in defrost, ice buildup on the outdoor coil, or a complete no-heat condition. Installing a new board restores correct cycle timing and reliable heating and cooling.\u003c\/p\u003e\n\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\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\u003ePart 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\u003eControl \/ Defrost Circuit 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; reversing valve sequencing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFitment\u003c\/td\u003e\n\u003ctd\u003eOEM\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003cp\u003eBuilt as the direct replacement for the ICP WPH4484000RKA1 heat pump condensing unit. Because ICP manufactures for multiple brands, this board also services equivalent Tempstar, Heil, Comfortmaker, and Arcoaire outdoor units originally equipped with part 1178001. Match the board's part number and connector layout to your existing board before installing.\u003c\/p\u003e\n\n\u003ch3\u003eInstallation Guide\u003c\/h3\u003e\n\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 before handling the board.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the service panel to expose the control compartment.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph every plug and wire on the old board; note the defrost timer setting (jumper or dip switch).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Unplug each connector, release the board standoffs or screws, and lift the board out.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Seat the new board, set the defrost timing to match the original, and reconnect every plug per your photo.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power, run a heating and cooling call, and confirm the compressor, reversing valve, and defrost cycle operate correctly.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eHeat pump won't start in heating or cooling despite a good thermostat signal.\u003c\/li\u003e\n\u003cli\u003eOutdoor coil ices over because the unit never enters defrost.\u003c\/li\u003e\n\u003cli\u003eUnit gets stuck in defrost or short-cycles the compressor.\u003c\/li\u003e\n\u003cli\u003eVisible scorch marks, burnt relays, or a cracked board.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eShipping \u0026amp; Returns\u003c\/h3\u003e\n\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":63021484245363,"sku":"WPH4484000RKA1","price":214.44,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":63047469498739,"sku":"WPH4484000RKA1-GEN","price":164.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-control-board-furnace-WPH4484000RKA1.jpg?v=1782885569","url":"https:\/\/nationalhvacparts.com\/products\/icp-control-board-for-wph4484000rka1-defrost-circuit-board-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}