{"product_id":"tempstar-defrost-control-board-for-t4h324gkd100-heat-pump-ships-today","title":"Tempstar Defrost Control Board for T4H324GKD100 — Heat Pump | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\n\u003cp\u003eThis OEM defrost control board (part number 1173636) is the genuine electronic brain for the Tempstar T4H324GKD100 heat pump's defrost cycle. It monitors the outdoor coil temperature sensor and the defrost timer interval, then commands the reversing valve, condenser fan, and auxiliary heat to clear frost and ice from the outdoor coil during cold-weather heating. When the board fails, the unit may ice over completely, run continuous or never-ending defrosts, fail to switch into heating, or lock the compressor out. Boards commonly fail from power surges, lightning, moisture intrusion, and burned relay contacts.\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\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\u003eTempstar (ICP \/ 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\u003eApplication\u003c\/td\u003e\n\u003ctd\u003eHeat Pump Defrost Control\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 for the Tempstar T4H324GKD100 heat pump and ICP-family heat pumps using the same defrost board platform. Tempstar, Heil and Comfortmaker share common controls, so this board cross-fits many sibling models — match the printed part number 1173636 and the board's 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 outdoor disconnect and verify zero voltage with a multimeter before touching the board.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the control-panel service cover to expose the defrost board.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph every harness connector and the defrost-timer jumper\/pin setting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Unplug each connector, release the board standoffs\/screws, and lift the old board out.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new board, set the defrost timer jumper to match the original, and reseat every connector per your photo.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and confirm normal heating operation; force a defrost test to verify the cycle initiates and terminates.\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 and never defrosts in heating mode\u003c\/li\u003e\n\u003cli\u003eUnit stuck in continuous defrost or won't enter heating\u003c\/li\u003e\n\u003cli\u003eNo 24V output to the reversing valve or fan during defrost\u003c\/li\u003e\n\u003cli\u003eVisible burn marks, corrosion, or a fried relay on the 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":"Tempstar","offers":[{"title":"Direct Replacement","offer_id":63021801013619,"sku":"1173636-GEN","price":189.0,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048440545651,"sku":"1173636","price":245.7,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-control-board-defrost-1173636_a5066d97-9006-42fc-ae4b-3aa84fc14d6f.jpg?v=1782959697","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-defrost-control-board-for-t4h324gkd100-heat-pump-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}