{"product_id":"tempstar-defrost-control-board-for-t4h360gkd400-heat-pump-ships-today","title":"Tempstar Defrost Control Board for T4H360GKD400 — Heat Pump | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThis OEM defrost control board (part 1173636) governs the defrost cycle on the Tempstar T4H360GKD400 heat pump. During heating operation, frost builds on the outdoor coil and chokes off airflow; the defrost board tracks elapsed time and coil temperature through the defrost sensor, then initiates a defrost — energizing the reversing valve, de-energizing the outdoor fan, and bringing on auxiliary heat so the indoor air stays warm while the coil clears. A failed defrost board is a leading cause of a heat pump that ices up solid, loses heating output, or runs costly emergency heat nonstop. Because the board orchestrates the reversing valve and fan relays, one failure can produce several symptoms at once.\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\u003eTempstar (ICP \/ Heil)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFunction\u003c\/td\u003e\n\u003ctd\u003eDefrost timing, reversing valve \u0026amp; fan control\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eApplication\u003c\/td\u003e\n\u003ctd\u003eHeat Pump Outdoor Unit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cp\u003eBuilt for the Tempstar T4H360GKD400 heat pump and shared ICP\/Heil\/Comfortmaker platforms using the 1173636 defrost board. Match the part number and connector layout on 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 breaker and outdoor disconnect; verify zero voltage with a multimeter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the control compartment access panel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph every connector and wire on the existing board before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Unplug each connector, release the standoffs or screws, and lift out the failed board.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new board and transfer each connector to its matching terminal per your photo, including the defrost sensor lead.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and run a forced\/test defrost to confirm the reversing valve, fan, and aux-heat outputs sequence correctly.\u003c\/li\u003e\n\u003c\/ol\u003e\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eOutdoor coil ices over with no defrost cycle\u003c\/li\u003e\n\u003cli\u003eHeat pump stuck on auxiliary\/emergency heat\u003c\/li\u003e\n\u003cli\u003eDefrost runs too frequently or never starts\u003c\/li\u003e\n\u003cli\u003eReversing valve or outdoor fan unresponsive during defrost\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":"Tempstar","offers":[{"title":"Direct Replacement","offer_id":63021790626163,"sku":"1173636-GEN","price":145.0,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048442872179,"sku":"1173636","price":188.5,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-control-board-defrost-1173636_020aebc4-3591-465d-a822-dc891f11e954.jpg?v=1782959775","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-defrost-control-board-for-t4h360gkd400-heat-pump-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}