{"product_id":"tempstar-defrost-control-board-for-t4h348gka100-heat-pump-ships-today","title":"Tempstar Defrost Control Board for T4H348GKA100 — 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 T4H348GKA100 heat pump's defrost cycle. It monitors the outdoor coil temperature sensor and accumulated run time, then commands the reversing valve and shuts off the outdoor fan to melt frost off the coil during cold-weather operation. A failed defrost board leaves the outdoor coil iced over, kills heating capacity, and can trip the system on high pressure.\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 \/ Heil \/ ICP\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, fan control\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eApplication\u003c\/td\u003e\n\u003ctd\u003eHeat Pump\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFits Model\u003c\/td\u003e\n\u003ctd\u003eT4H348GKA100\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 T4H348GKA100 and matching ICP-family heat pumps (Heil, Comfortmaker, ICP) using defrost board 1173636. Match the 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 and verify zero voltage with a multimeter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the condenser control-panel cover.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph every wire harness and the defrost timing pin\/jumper setting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Unplug connectors, release the board standoffs, and lift the old board out.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Seat the new board on the standoffs, reconnect each harness, 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 normal heat-pump operation and 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 up and never defrosts\u003c\/li\u003e\n\u003cli\u003eHeat pump won't switch to defrost or stays in defrost\u003c\/li\u003e\n\u003cli\u003eNo 24V output to the reversing valve or fan\u003c\/li\u003e\n\u003cli\u003eVisible burn marks, scorched traces, or a failed relay on the board\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 uninstalled parts. Backed by the National HVAC Parts fitment guarantee.\u003c\/p\u003e","brand":"Tempstar","offers":[{"title":"Direct Replacement","offer_id":63021793083763,"sku":"1173636-GEN","price":125.0,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048442216819,"sku":"1173636","price":162.5,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-control-board-defrost-1173636_af87e883-448c-43d0-863b-f0e0cf726d4c.jpg?v=1782959749","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-defrost-control-board-for-t4h348gka100-heat-pump-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}