{"product_id":"tempstar-defrost-control-board-for-t4h318gka200-heat-pump-defrost-ships-today","title":"Tempstar Defrost Control Board for T4H318GKA200 — Heat Pump Defrost | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThe OEM defrost control board (part #1173636) governs the defrost cycle on the Tempstar T4H318GKA200 heat pump. It reads coil temperature and run time, then triggers the reversing valve, outdoor fan, and supplemental heat to melt frost off the outdoor coil. A bad board commonly shows up as an outdoor unit caked in ice, a heat pump stuck in one mode, short-cycling, or no 24V output to downstream components. Replacing the board with this factory part restores proper defrost logic.\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\u003eApplication\u003c\/td\u003e\n\u003ctd\u003eHeat Pump Outdoor Unit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFunction\u003c\/td\u003e\n\u003ctd\u003eTimed \/ demand defrost control\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cp\u003eFactory replacement for the Tempstar T4H318GKA200 heat pump condenser, and shared across many same-era ICP-family heat pumps (Heil, Comfortmaker, Arcoaire). Confirm original part number 1173636 before ordering.\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 cover from the condensing unit.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph every wire, connector, and sensor lead before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Unplug the low-voltage harness and sensor, then unscrew the old board from its standoffs.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new board, reconnect each lead per your photos, and reattach the defrost sensor to the coil.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and run a forced defrost test to verify the reversing valve and fan respond.\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 won't change between heat and cool\u003c\/li\u003e\n\u003cli\u003eNo 24V output to reversing valve or contactor\u003c\/li\u003e\n\u003cli\u003eScorched relays, corrosion, or burn marks on the board\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":63021803143539,"sku":"1173636-GEN","price":149.0,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048440217971,"sku":"1173636","price":193.7,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-control-board-defrost-1173636_42eb0748-f3e2-4c15-a9d7-b1b4fc9e603e.jpg?v=1782959683","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-defrost-control-board-for-t4h318gka200-heat-pump-defrost-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}