The Honeywell RA890F1478 Gas Furnace Primary Control is a replacement control module that governs the furnace’s ignition and essential safety sequence. This unit operates on 120V with a 3-wire connection and is supplied with no cover. It includes a 15-second safety timer to enforce proper shutdown in fault conditions. Used as the primary control in gas furnaces, it coordinates the furnace sequence and safety interlocks to support safe, reliable operation.
