{"product_id":"tempstar-defrost-control-board-for-t4h330gkd100-heat-pump-ships-today","title":"Tempstar Defrost Control Board for T4H330GKD100 — Heat Pump | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThis OEM Tempstar defrost control board (part number 1173636) manages the defrost cycle on the T4H330GKD100 heat pump. In heating mode the outdoor coil collects frost, and the defrost board monitors coil temperature and run time, then commands a defrost — reversing the valve, shutting the outdoor fan, and energizing auxiliary heat — to melt accumulated ice. It also coordinates the contactor and reversing-valve solenoid through the low-voltage circuit. When this board fails, the outdoor coil ices over and stays iced, heating capacity drops, and the unit may lock out or run continuously without ever clearing frost. Erratic defrost timing, a unit stuck in defrost, or no defrost at all are classic symptoms of a failing board.\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\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\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 section)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cp\u003eDirect OEM replacement for the Tempstar T4H330GKD100 heat pump and related ICP-family (Heil, Comfortmaker) outdoor units that originally used defrost board 1173636. Verify the board part number printed on your existing board before ordering, as defrost logic and pin-outs vary by model.\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 outdoor disconnect and verify zero voltage with a multimeter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the control-panel access cover.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph every connector and the defrost-timing pin\/jumper position before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Unplug all harness connectors and unsnap or unscrew the board from its standoffs.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Seat the new board, reconnect each 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 and confirm a normal startup; force a defrost test per the unit's procedure if needed.\u003c\/li\u003e\n\u003c\/ol\u003e\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eOutdoor coil ices over and never clears in heating mode\u003c\/li\u003e\n\u003cli\u003eUnit stuck in defrost or never enters defrost\u003c\/li\u003e\n\u003cli\u003eErratic reversing-valve switching or no auxiliary heat during defrost\u003c\/li\u003e\n\u003cli\u003eBoard shows burnt traces, scorched relays, or no output\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eShipping \u0026amp; Returns\u003c\/h3\u003e\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":63021800325491,"sku":"1173636-GEN","price":185.0,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048440906099,"sku":"1173636","price":240.5,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-control-board-defrost-1173636_b73a67d9-c753-445f-bf03-ea00020accd8.jpg?v=1782959711","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-defrost-control-board-for-t4h330gkd100-heat-pump-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}