{"product_id":"tempstar-defrost-control-board-for-txh537gka200-heat-pump-ships-today","title":"Tempstar Defrost Control Board for TXH537GKA200 — Heat Pump | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\n\u003cp\u003eThis OEM defrost control board (part number 1173636) is the brain of the outdoor section on your Tempstar TXH537GKA200 heat pump. It monitors coil temperature and run time, initiates and terminates the defrost cycle, switches the reversing valve, and sequences the compressor and condenser fan. When it fails, the outdoor coil can ice over in heating mode, the system may get stuck in defrost, or the heat pump may fail to switch between heating and cooling. A failed board is a frequent cause of poor winter heating performance and frozen outdoor coils.\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 and fan sequencing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003cp\u003eDesigned for the Tempstar TXH537GKA200 heat pump and used across matching ICP-family outdoor units (Tempstar, Heil, Comfortmaker, ICP). Verify the board layout, connector style, and part number against 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 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 and connector position on the board before removing anything.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Unplug the harnesses, release the 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 harness exactly per your photo.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power, run a heating call, and confirm proper defrost initiation and reversing valve operation.\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 frosts or ices over and never clears in heating mode.\u003c\/li\u003e\n\u003cli\u003eSystem gets stuck running a continuous defrost cycle.\u003c\/li\u003e\n\u003cli\u003eHeat pump fails to switch between heating and cooling.\u003c\/li\u003e\n\u003cli\u003eNo 24V output to the reversing valve, fan, or compressor contactor.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eShipping \u0026amp; Returns\u003c\/h3\u003e\n\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":63021625082227,"sku":"1173636-GEN","price":154.95,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048449130867,"sku":"1173636","price":201.44,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-control-board-defrost-1173636_499222f1-4fb6-4177-8aab-d8ec36862340.jpg?v=1782960004","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-defrost-control-board-for-txh537gka200-heat-pump-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}