{"product_id":"tempstar-defrost-control-board-for-t4h736gka100-heat-pump-ships-today","title":"Tempstar Defrost Control Board for T4H736GKA100 — Heat Pump | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThis OEM defrost control board (part 1173636) is the brain of the Tempstar T4H736GKA100 heat pump's defrost cycle. It monitors coil temperature and run time, then triggers a defrost cycle — energizing the reversing valve, stopping the outdoor fan, and activating auxiliary heat — to clear frost from the outdoor coil in cold weather. When the board fails, the heat pump either never defrosts (ice builds up on the coil and efficiency collapses) or defrosts constantly. Symptoms include a frozen outdoor coil, no heat or weak heat, the outdoor fan behaving erratically, or no response to a defrost call.\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\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\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\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cp\u003eDesigned for the Tempstar T4H736GKA100 heat pump and matching ICP \/ Heil \/ Comfortmaker units that use the 1173636 defrost board. Always match the exact part number on your existing board, as defrost boards vary by platform and timing scheme.\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 condenser service panel to reach the control box.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph every wire harness and connector position before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Unplug the harnesses, release the standoffs or screws, and lift out the old board.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new board, set any defrost timing jumper to match the original, and reconnect all harnesses per your photo.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and initiate a defrost test per the board's instructions to confirm 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 never clears\u003c\/li\u003e\n\u003cli\u003eHeat pump won't produce heat or runs in constant defrost\u003c\/li\u003e\n\u003cli\u003eOutdoor fan stops or cycles erratically\u003c\/li\u003e\n\u003cli\u003eNo reversing valve or aux-heat action on a defrost call\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":63021781418355,"sku":"1173636-GEN","price":149.95,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048447197555,"sku":"1173636","price":194.94,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-control-board-defrost-1173636_209c1639-2747-4e57-9bed-a756e3d85905.jpg?v=1782959927","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-defrost-control-board-for-t4h736gka100-heat-pump-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}