{"product_id":"tempstar-defrost-control-board-for-t2h318gka100-heat-pump-oem-1173636-ships-today","title":"Tempstar Defrost Control Board for T2H318GKA100 — Heat Pump OEM 1173636 | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\n\u003cp\u003eThis is the genuine OEM Tempstar defrost control board (part number 1173636) for the T2H318GKA100 heat pump. The defrost control board is the brain of your heat pump's defrost cycle: it monitors coil temperature and run time, then initiates and terminates defrost to clear ice from the outdoor coil during heating mode. It also coordinates the reversing valve and outdoor fan during defrost. When this board fails, the heat pump can either skip defrost entirely — letting the coil ice over and killing efficiency — or get stuck in defrost, blowing cold air indoors and triggering auxiliary heat far more than necessary. Common failure symptoms include a permanently iced outdoor unit, no auxiliary heat staging, intermittent no-heat calls, and visible scorch marks or relay chatter on the board itself.\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\u003eFits Model\u003c\/td\u003e\n\u003ctd\u003eT2H318GKA100\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eApplication\u003c\/td\u003e\n\u003ctd\u003eHeat Pump Defrost Control\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFitment\u003c\/td\u003e\n\u003ctd\u003eOEM Replacement\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003cp\u003eThis board is the factory-specified defrost control for the Tempstar T2H318GKA100 heat pump and the shared ICP \/ Heil \/ Comfortmaker platforms that use part 1173636. Always confirm the part number printed on your existing board before ordering, as defrost boards across the ICP family look similar but differ in timing logic and terminal layout.\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 the breaker, then verify zero voltage at the board with a multimeter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the control-box access panel on the outdoor unit.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph every wire and terminal position before disconnecting anything.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Label and disconnect the low-voltage and line-voltage leads, then unclip or unscrew the old defrost board from its standoffs.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new board on the standoffs and reconnect each wire exactly as photographed, including the defrost thermostat and sensor leads.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and confirm normal heating operation, then verify a defrost cycle initiates and terminates correctly.\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 never clears during heating mode\u003c\/li\u003e\n\u003cli\u003eUnit gets stuck in defrost, blowing cold air indoors\u003c\/li\u003e\n\u003cli\u003eAuxiliary\/emergency heat runs constantly or won't stage\u003c\/li\u003e\n\u003cli\u003eVisible burn marks, corrosion, or chattering relays on the board\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 on unused parts. Backed by the National HVAC Parts fitment guarantee.\u003c\/p\u003e","brand":"Tempstar","offers":[{"title":"Direct Replacement","offer_id":63021822607731,"sku":"1173636-GEN","price":124.95,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048438514035,"sku":"1173636","price":162.44,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-control-board-defrost-1173636_b17a342c-b5b0-4739-b535-90792bcfe55f.jpg?v=1782959610","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-defrost-control-board-for-t2h318gka100-heat-pump-oem-1173636-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}