{"product_id":"icp-defrost-control-board-for-wph4424000rka1-24v-heat-pump-ships-today-1","title":"ICP Defrost Control Board for WPH4424000RKA1 — 24V Heat Pump | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\n\u003cp\u003eThis OEM control board (Part No. 1178001) is the brain of your ICP \/ Tempstar \/ Heil WPH4424000RKA1 heat pump. It manages the defrost cycle, sequences the compressor and condenser fan, switches the reversing valve for heat\/cool changeover, and protects the system with timed anti-short-cycle logic. Built on 24V control inputs, the board reads the defrost thermostat and reversing-valve signal to keep the outdoor coil clear of frost in heating mode. A failed board commonly causes no-heat, no-defrost, ice-up on the outdoor coil, or a unit that won't switch between 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\u003eDefrost \/ Heat Pump Control Circuit Board\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eICP (Tempstar \/ Heil \/ Comfortmaker)\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, reversing valve, compressor sequencing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFits Model\u003c\/td\u003e\n\u003ctd\u003eWPH4424000RKA1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003cp\u003eDesigned for the ICP\/Tempstar\/Heil WPH4424000RKA1 packaged heat pump and used across matching ICP-family WPH-series control assemblies. Match the board's connector layout and pin count 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 and verify zero voltage with a multimeter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the control-box service panel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph every plug, terminal, and the defrost-timer jumper position before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Unplug the harnesses and unclip\/unscrew the old board from its standoffs.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new board, reconnect each harness per your photo, and set the defrost timer jumper to match.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and confirm normal startup, changeover, and a forced defrost cycle if accessible.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eOutdoor coil ices over with no defrost cycle in heating.\u003c\/li\u003e\n\u003cli\u003eUnit won't switch between heating and cooling modes.\u003c\/li\u003e\n\u003cli\u003eCompressor or fan won't sequence on, or short-cycles.\u003c\/li\u003e\n\u003cli\u003eVisible burnt traces, scorched 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 before 3 PM CST. 30-day returns. Backed by the National HVAC Parts fitment guarantee.\u003c\/p\u003e","brand":"ICP","offers":[{"title":"OEM","offer_id":63027203342707,"sku":"1178001","price":223.6,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":63047497023859,"sku":"1178001-GEN","price":172.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-control-board-defrost-1178001_0aeb52da-1dbb-45b9-b720-0e383f007980.jpg?v=1782886608","url":"https:\/\/nationalhvacparts.com\/products\/icp-defrost-control-board-for-wph4424000rka1-24v-heat-pump-ships-today-1","provider":"National HVAC Parts","version":"1.0","type":"link"}