{"product_id":"tempstar-control-board-for-t4a436gkd100-comfortalert-diagnostic-module-ships-today","title":"Tempstar Control Board for T4A436GKD100 — ComfortAlert Diagnostic Module | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\n\u003cp\u003eThis is a genuine OEM ComfortAlert control board (OEM part #1177402) for the Tempstar T4A436GKD100 condensing unit. The ComfortAlert module continuously monitors compressor electrical operation and reports fault conditions — locked rotor, open circuit, low voltage, short cycling, and welded contactor — through a diagnostic LED, giving technicians a fast read on system health without a full teardown. By guarding the compressor against repeated fault-condition starts, this board extends compressor life and cuts troubleshooting time. When it fails, you may get no diagnostic feedback, a unit that ignores a cooling call, or erratic compressor protection behavior. Replacing it restores proper monitoring and the protective lockouts that keep the compressor safe.\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\u003e1177402\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eComfortAlert Diagnostic 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\u003e24V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFunction\u003c\/td\u003e\n\u003ctd\u003eCompressor diagnostics, protection \u0026amp; fault LED\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 as a direct-fit replacement for the Tempstar T4A436GKD100 air conditioning condenser. The same ComfortAlert module is shared across many ICP-family condensers and heat pumps (Heil, Comfortmaker, Arcoaire) of the same generation. Verify the part number 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 disconnect and breaker, then confirm zero voltage at the board 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 low-voltage and sensing lead and its terminal position on the board.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Unplug the harness connectors, 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 connector exactly per your photo.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power, call for cooling, and confirm the diagnostic LED shows normal operation with no fault codes.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eDiagnostic LED is dark or stuck on a fault with no actual fault present.\u003c\/li\u003e\n\u003cli\u003eCompressor will not start despite a valid 24V cooling call.\u003c\/li\u003e\n\u003cli\u003eNuisance lockouts or short cycling that clear when the board is bypassed.\u003c\/li\u003e\n\u003cli\u003eVisible burn marks, swollen capacitors, or corrosion on the board.\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":63021805535603,"sku":"1177402-GEN","price":168.95,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048437236083,"sku":"1177402","price":219.63,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-control-board-furnace-1177402_4a2062d4-1018-406c-b341-6be0479fc216.jpg?v=1782959563","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-control-board-for-t4a436gkd100-comfortalert-diagnostic-module-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}