{"product_id":"tempstar-defrost-control-board-for-t4h524gka100-heat-pump-defrost-ships-today","title":"Tempstar Defrost Control Board for T4H524GKA100 — Heat Pump Defrost | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThis genuine OEM defrost control board (OEM 1173636, DEFROST CONTROL BOARD) manages the defrost cycle on the Tempstar T4H524GKA100 heat pump. It monitors the defrost thermostat and timing intervals, then commands the reversing valve and shuts off the outdoor fan to melt frost off the outdoor coil during winter operation. A failed board causes excessive coil icing, no defrost, short cycling, or a unit that won't switch into heating properly. Replacing it restores correct, efficient heat-pump operation.\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 (ICP \/ Heil family)\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 and fan control\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 T4H524GKA100 heat pump and shared across matching ICP\/Heil\/Comfortmaker outdoor units. Confirm the OEM part number, board layout, and connector configuration against your existing board 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 disconnect 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 to expose the board.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph every connector and wire position before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Unplug the connectors, release the board's mounting 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 the standoffs and reconnect each plug and wire exactly per your photo.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power, initiate a defrost (or force one per the board's test pins), and confirm correct reversing-valve and fan 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 heavily and never defrosts\u003c\/li\u003e\n\u003cli\u003eHeat pump short cycles or won't enter heating mode\u003c\/li\u003e\n\u003cli\u003eReversing valve or outdoor fan don't respond during defrost\u003c\/li\u003e\n\u003cli\u003eNo board activity \/ status LED dark with power applied\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":63021782958451,"sku":"1173636-GEN","price":98.0,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048446312819,"sku":"1173636","price":127.4,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-control-board-defrost-1173636_8888719e-bacd-4c40-89b7-fb691b2f324b.jpg?v=1782959890","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-defrost-control-board-for-t4h524gka100-heat-pump-defrost-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}