{"product_id":"tempstar-defrost-control-board-for-t4h736gkb100-24v-heat-pump-ships-today","title":"Tempstar Defrost Control Board for T4H736GKB100 — 24V Heat Pump | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\n\u003cp\u003eThis genuine OEM defrost control board (part number 1173636) is the brain of the Tempstar T4H736GKB100 heat pump's defrost cycle. In heating mode, the outdoor coil accumulates frost; the defrost board monitors elapsed run time and the defrost thermostat, then periodically reverses the system into a brief cooling cycle to melt that frost while energizing supplemental heat for comfort. The board manages the reversing valve, outdoor fan, and defrost timing intervals. When it fails, the heat pump can ice over heavily in winter, run inefficiently, short-cycle, or fail to switch between heating and cooling. Because it carries 24V control logic and switches multiple outputs, a damaged board is a frequent cause of poor cold-weather heat-pump performance.\u003c\/p\u003e\n\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\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\u003e24 VAC\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\u003eFits Model\u003c\/td\u003e\n\u003ctd\u003eT4H736GKB100\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003cp\u003eDirectly fits the Tempstar T4H736GKB100 heat pump and other ICP-family (Heil, Comfortmaker, Tempstar) heat pumps that specify OEM defrost board 1173636. Confirm the part number printed on your existing board before ordering.\u003c\/p\u003e\n\n\u003ch3\u003eInstallation Guide\u003c\/h3\u003e\n\u003col\u003e\n\u003cli\u003e\n\u003cstrong\u003eSafety First\u003c\/strong\u003e — Disconnect power at the outdoor disconnect and breaker. Verify zero voltage with a multimeter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the condenser unit's electrical access panel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph every wire and connector on the board before disconnecting; label as needed.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Disconnect the low-voltage and line connections, then unscrew or unclip the old board from its standoffs.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new board and reconnect each lead exactly per your photo, seating connectors fully.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and confirm normal heating operation; if accessible, initiate a forced defrost to verify the cycle.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eOutdoor coil ices over and won't clear in heating mode\u003c\/li\u003e\n\u003cli\u003eHeat pump won't switch between heating and cooling\u003c\/li\u003e\n\u003cli\u003eShort-cycling or no defrost cycle at all\u003c\/li\u003e\n\u003cli\u003eAuxiliary\/emergency heat runs constantly or never engages\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eShipping \u0026amp; Returns\u003c\/h3\u003e\n\u003cp\u003eShips same day on orders placed 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":63021781287283,"sku":"1173636-GEN","price":139.0,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048447328627,"sku":"1173636","price":180.7,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-control-board-defrost-1173636_a3fdb77f-90a1-45f7-8154-214ed491a92d.jpg?v=1782959931","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-defrost-control-board-for-t4h736gkb100-24v-heat-pump-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}