{"product_id":"tempstar-defrost-control-board-for-t4h442gka100-heat-pump-ships-today","title":"Tempstar Defrost Control Board for T4H442GKA100 — Heat Pump | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThis genuine OEM defrost control board (part 1173636) is the brain of the Tempstar T4H442GKA100 heat pump's defrost system. It monitors coil temperature and run time, then initiates and terminates defrost cycles to clear frost from the outdoor coil in heating mode. The board coordinates the reversing valve, condenser fan, and auxiliary heat during defrost. When it fails, the heat pump may ice over in winter, run continuous or no defrost cycles, short cycle, or fail to switch modes. This OEM board restores correct defrost timing and reliable cold-weather heating.\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\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 T4H442GKA100 heat pump and related ICP\/Heil family units specifying OEM part 1173636. Match the board's connector layout and part number to your original 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 verify zero voltage with a multimeter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the condenser control\/electrical panel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph every wire harness, plug, and DIP\/jumper setting before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Unplug the connectors, release the board standoffs or screws, and lift out the old board.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Seat the new board on its standoffs, match any jumper\/DIP settings to the original, and reconnect every harness per your photo.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power, run a heating cycle, and force a defrost test to confirm correct operation.\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 won't defrost in winter\u003c\/li\u003e\n\u003cli\u003eHeat pump runs constant defrost or never defrosts\u003c\/li\u003e\n\u003cli\u003eSystem short cycles or fails to switch heat\/cool modes\u003c\/li\u003e\n\u003cli\u003eNo board LED activity or fault codes on the diagnostic light\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":63021785743731,"sku":"1173636-GEN","price":145.0,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048444445043,"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_a5c2b181-7944-4b2b-a174-9ed1f905447d.jpg?v=1782959841","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-defrost-control-board-for-t4h442gka100-heat-pump-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}