{"product_id":"icp-furnace-control-board-kit-for-rgs121hdcb0aaa-oem-replacement-ships-today","title":"ICP Furnace Control Board Kit for RGS121HDCB0AAA — OEM Replacement | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\n\u003cp\u003eThis genuine OEM furnace control board kit (OEM 1183618) is the brain of the ICP \/ Heil \/ Tempstar RGS121HDCB0AAA gas furnace. The integrated furnace control sequences the entire heat cycle: it reads the thermostat call, runs the inducer and pressure-switch proving, energizes the hot surface igniter, opens the gas valve, monitors flame via the sensor, and times the blower on\/off delays. It also manages safety lockouts and flashes diagnostic fault codes through its onboard LED. When the board fails — from voltage surges, heat stress, or failed relays — the furnace may short cycle, fail to ignite, run the blower constantly, or go completely dead. This board kit ships with the mounting hardware and connectors needed for a clean swap and restores correct, safe sequencing.\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\u003eOEM Part 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 \/ Heil \/ Tempstar\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFunction\u003c\/td\u003e\n\u003ctd\u003eIgnition, Blower \u0026amp; Safety Control\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDiagnostics\u003c\/td\u003e\n\u003ctd\u003eOnboard LED Fault Codes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFitment\u003c\/td\u003e\n\u003ctd\u003eOEM Replacement Kit\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 OEM replacement kit for the ICP \/ Heil \/ Tempstar RGS121HDCB0AAA gas furnace. The same control platform is shared across several ICP-family furnace models. Verify the board's connector layout and part number against your existing control 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 — Shut off gas and disconnect power, then verify zero voltage with a multimeter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the blower-compartment service panel to expose the control board.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph every harness plug and its position before unplugging anything.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Unplug each connector, remove the mounting screws\/standoffs, and lift out the old board.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new board, transfer any jumpers\/links, and reconnect each harness to the matching plug per your photos.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore gas and power, run a full heat cycle, and confirm a steady LED with correct 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 on a heat call, or no LED at all on the board.\u003c\/li\u003e\n\u003cli\u003eShort cycling, random lockouts, or repeating fault-code flashes.\u003c\/li\u003e\n\u003cli\u003eBlower runs continuously or never starts.\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 on orders placed 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":63027537019251,"sku":"1183618","price":214.5,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":63047554957683,"sku":"1183618-GEN","price":165.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-control-board-furnace-1183618_33e76f67-26a2-47bf-918c-24fbff14df9b.jpg?v=1782889079","url":"https:\/\/nationalhvacparts.com\/products\/icp-furnace-control-board-kit-for-rgs121hdcb0aaa-oem-replacement-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}