{"product_id":"icp-furnace-control-board-kit-for-rgs121ltcb0aaa-oem-1183618-ships-today","title":"ICP Furnace Control Board Kit for RGS121LTCB0AAA — OEM 1183618 | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\n\u003cp\u003eThis OEM integrated furnace control (IFC) board kit is the brain of the ICP \/ Tempstar \/ Heil RGS121LTCB0AAA gas furnace. It manages the ignition sequence, inducer and blower timing, gas valve, flame sensing, and all safety lockouts. A failed board produces erratic behavior — blower that won't shut off, no ignition, short cycling, or a furnace that's completely dead despite good power. OEM part \u003cstrong\u003e1183618\u003c\/strong\u003e ships as a kit with the correct connectors and mounting hardware to drop straight into the RGS121 control box.\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\u003e1183618\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eIntegrated Furnace Control Board (kit)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eICP \/ Tempstar \/ Heil\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eApplication\u003c\/td\u003e\n\u003ctd\u003eSingle-stage gas furnace\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVoltage\u003c\/td\u003e\n\u003ctd\u003e120V primary \/ 24V control\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFit\u003c\/td\u003e\n\u003ctd\u003eOEM direct 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\u003eDirect-fit replacement for the ICP Tempstar Heil RGS121LTCB0AAA furnace and ICP-family models that originally shipped with control board 1183618. Confirm your old board part number and connector layout before installing.\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 furnace switch and breaker; verify zero voltage with a multimeter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the blower \/ control compartment service panel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph every wire and connector on the board before disconnecting anything.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Unplug all harnesses, remove the mounting screws, and lift out the old board.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new 1183618 board, reconnect each harness exactly per your photo, and set any DIP switches to match the original.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power, run a full heat cycle, and confirm proper ignition, blower timing, and 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\u003eFurnace completely dead with confirmed 120V supply.\u003c\/li\u003e\n\u003cli\u003eBlower runs continuously or won't start.\u003c\/li\u003e\n\u003cli\u003eNo ignition sequence or random short cycling.\u003c\/li\u003e\n\u003cli\u003eVisible burns, corrosion, or blown components 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":"ICP","offers":[{"title":"OEM","offer_id":63027466305907,"sku":"1183618","price":245.7,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":63047555842419,"sku":"1183618-GEN","price":189.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-control-board-furnace-1183618_eb529add-fecd-4142-a9f9-8e7ef226e6c4.jpg?v=1782889115","url":"https:\/\/nationalhvacparts.com\/products\/icp-furnace-control-board-kit-for-rgs121ltcb0aaa-oem-1183618-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}