{"product_id":"tempstar-defrost-control-board-for-t4h448gkb200-heat-pump-ships-today","title":"Tempstar Defrost Control Board for T4H448GKB200 — Heat Pump | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThis is the OEM defrost control board for the Tempstar T4H448GKB200 heat pump (OEM part 1173636). The defrost board monitors the defrost thermostat and timer to determine when frost has built up on the outdoor coil, then initiates a defrost cycle — reversing the valve, shutting off the outdoor fan, and energizing auxiliary heat to protect comfort. It also manages compressor anti-short-cycle timing and contactor signaling. A failed defrost board causes a heat pump to ice over in winter, skip or get stuck in defrost, or fail to energize the outdoor unit at all.\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 AC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eApplication\u003c\/td\u003e\n\u003ctd\u003eHeat Pump Defrost \/ Compressor Control\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cp\u003eDirect factory replacement for the Tempstar T4H448GKB200 heat pump and ICP\/Heil\/Comfortmaker units built on the same outdoor control platform. Match the board's part number and connector layout to 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; verify zero voltage with a multimeter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the condensing unit control-box panel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph every plug, terminal, and jumper\/pin setting on the old board.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Unplug the harnesses, release the board standoffs\/screws, and lift the board out.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Seat the new board on the standoffs, transfer any defrost-timer pin selection, and reconnect each harness per your photo.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and confirm normal heat-pump operation and a proper defrost initiation.\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 defrosts\u003c\/li\u003e\n\u003cli\u003eHeat pump stuck in continuous defrost\u003c\/li\u003e\n\u003cli\u003eOutdoor unit won't energize on a heat\/cool call\u003c\/li\u003e\n\u003cli\u003eNo 24V output to the contactor or reversing valve\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":63021784433011,"sku":"1173636-GEN","price":95.0,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048445329779,"sku":"1173636","price":123.5,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-control-board-defrost-1173636_cbaed8c2-1fb1-4cab-9fb2-28d157ee8108.jpg?v=1782959862","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-defrost-control-board-for-t4h448gkb200-heat-pump-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}