{"product_id":"icp-defrost-control-board-for-wch3484gka1-heat-pump-defrost-board-ships-today-1","title":"ICP Defrost Control Board for WCH3484GKA1 — Heat Pump Defrost Board | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThis genuine OEM defrost control board (OEM part number 1173636) manages the defrost cycle on ICP, Heil, and Tempstar heat pumps. The board monitors the defrost thermostat and a timed interval, then initiates a defrost cycle — reversing the valve, stopping the outdoor fan, and energizing auxiliary heat — to melt frost off the outdoor coil during cold-weather operation. It also coordinates compressor timing and lockout protection. A failed defrost board leaves the outdoor coil iced over, killing heating efficiency and risking compressor damage.\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\u003e1173636\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eDefrost Control Board\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eICP \/ Heil \/ Tempstar\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\u003eApplication\u003c\/td\u003e\n\u003ctd\u003eHeat Pump Defrost Control\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFitment\u003c\/td\u003e\n\u003ctd\u003eOEM Replacement\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cp\u003eDirectly fits ICP\/Heil\/Tempstar heat pump model WCH3484GKA1 and other units using this defrost control board. Confirm the board layout, connector positions, and defrost timing pin options match 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 condenser\/heat pump service panel to reach the control board.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph every connector and the defrost timing jumper position before removing anything.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Unplug each harness, note the defrost thermostat and sensor leads, and unscrew the board from its standoffs.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new board, reconnect every harness per your photo, and set the defrost timing pin to match the original.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power, run the unit in heating, and (if needed) force a defrost test to confirm the cycle initiates and terminates correctly.\u003c\/li\u003e\n\u003c\/ol\u003e\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eOutdoor coil ices up and never defrosts in heating mode.\u003c\/li\u003e\n\u003cli\u003eSystem runs constant defrost or won't exit defrost.\u003c\/li\u003e\n\u003cli\u003eNo response from the board despite proper 24V input.\u003c\/li\u003e\n\u003cli\u003eVisible burnt traces, scorched relays, or a failed onboard relay.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eShipping \u0026amp; Returns\u003c\/h3\u003e\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":63027252232563,"sku":"1173636","price":145.6,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":63047492108659,"sku":"1173636-GEN","price":112.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-control-board-defrost-1173636_190a9f66-656b-4994-80d2-f88f296011fe.jpg?v=1782886492","url":"https:\/\/nationalhvacparts.com\/products\/icp-defrost-control-board-for-wch3484gka1-heat-pump-defrost-board-ships-today-1","provider":"National HVAC Parts","version":"1.0","type":"link"}