{"product_id":"tempstar-defrost-control-board-for-t4h424gkd200-heat-pump-ships-today","title":"Tempstar Defrost Control Board for T4H424GKD200 — Heat Pump | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\n\u003cp\u003eThis is the genuine OEM defrost control board (part number 1173636) for the Tempstar T4H424GKD200 heat pump. The defrost control board governs the outdoor unit's defrost cycle — monitoring coil temperature and accumulated run time, then commanding the reversing valve and outdoor fan to melt frost and ice off the outdoor coil during heating operation. It also enforces compressor timing, anti-short-cycle delays, and auxiliary heat staging. A failed board leaves the coil iced over, the unit running nonstop without heat, or the defrost cycle never initiating or never terminating. Installing the correct OEM board restores proper defrost logic and protects the compressor from damage.\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 family)\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\n\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003cp\u003eDirect OEM replacement for the Tempstar T4H424GKD200 heat pump. This board (1173636) is shared across closely related ICP-family heat pump platforms including Heil and Comfortmaker. Verify the part number printed on your existing board before ordering.\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 breaker. Verify zero voltage with a multimeter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the control panel access cover on the outdoor unit.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph every wire and connector on the existing board before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Unplug the harnesses, release the mounting tabs or screws, and lift out the old board.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new board in the same orientation and reconnect each harness exactly per your photos.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power, run the unit in heat mode, and confirm the defrost cycle starts and ends correctly.\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.\u003c\/li\u003e\n\u003cli\u003eUnit runs continuously in cold weather without heating.\u003c\/li\u003e\n\u003cli\u003eReversing valve or outdoor fan unresponsive during defrost.\u003c\/li\u003e\n\u003cli\u003eNo status LEDs or erratic fault-code blinking on the 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":"Tempstar","offers":[{"title":"Direct Replacement","offer_id":63021787480435,"sku":"1173636-GEN","price":135.0,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048443593075,"sku":"1173636","price":175.5,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-control-board-defrost-1173636_f24ae083-e1c7-4b1e-93eb-6f894a836830.jpg?v=1782959806","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-defrost-control-board-for-t4h424gkd200-heat-pump-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}