{"product_id":"icp-furnace-control-board-kit-for-rgs121srca0aaa-oem-1183618-ships-today","title":"ICP Furnace Control Board Kit for RGS121SRCA0AAA — OEM 1183618 | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\n\u003cp\u003eThis OEM control board kit, part number 1183618, is the integrated furnace control (IFC) that runs the entire heating sequence on the ICP \/ Tempstar \/ Heil RGS121SRCA0AAA gas furnace. The board manages igniter timing, gas valve actuation, inducer and blower relays, and all safety interlocks from the pressure switch and limit circuits. When the board fails, the furnace can lose heat entirely, lock out on diagnostic flash codes, run the blower continuously, or fail to sequence ignition. Because the IFC ties together every major furnace component, installing the correct OEM replacement is the surest way to restore proper, code-compliant operation rather than chasing intermittent faults. The kit ships with the board and mounting hardware needed for a direct swap.\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\u003eLine Voltage\u003c\/td\u003e\n\u003ctd\u003e120V\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\u003eApplication\u003c\/td\u003e\n\u003ctd\u003eGas Furnace Control\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFitment\u003c\/td\u003e\n\u003ctd\u003eRGS121SRCA0AAA\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 ICP \/ Tempstar \/ Heil RGS121SRCA0AAA gas furnace and related RGS121 models using the same control platform. Match the printed board number against your existing IFC before ordering, as ICP used several board revisions across this series.\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, and shut off the gas. Verify zero voltage with a multimeter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the furnace control\/blower compartment service panel.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph every connector and wire on the existing board before disconnecting; label any in question.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Unplug all harness connectors, remove the board mounting screws or standoffs, and lift out the old control.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new board and reconnect each harness exactly per your photos. Confirm no pins are bent or mis-seated.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore gas and power, run a full heat cycle, and verify the diagnostic LED shows a normal code with proper ignition and blower timing.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eNo response to a heat call despite good igniter, gas, and thermostat.\u003c\/li\u003e\n\u003cli\u003eDiagnostic LED shows a hard-lockout or internal-fault flash code.\u003c\/li\u003e\n\u003cli\u003eBlower or inducer runs continuously or won't start.\u003c\/li\u003e\n\u003cli\u003eVisible burnt traces, scorched relays, or a burnt smell 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":63027448545651,"sku":"1183618","price":246.94,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":63047556104563,"sku":"1183618-GEN","price":189.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-control-board-furnace-1183618_8be2fd3c-2bf1-45ba-8222-677c6791fd35.jpg?v=1782889125","url":"https:\/\/nationalhvacparts.com\/products\/icp-furnace-control-board-kit-for-rgs121srca0aaa-oem-1183618-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}