HSCI 7-405-I Furnace Control Board | HSCI 1840 - F68LU

HSCI 7-405-I Furnace Control Board | HSCI 1840 | Direct Spark Ignition | Tested Condition: Used – Clean, Tested & Fully Working Availability: Ready for Pickup / Fast Response Key Specifications Brand: HSCI OEM Applications: Lennox Gas Furnaces Residential Gas Unit Heaters Other HSCI-equipped heating systems Part Number: 7-405-I Secondary Number: HSCI 1840 Board Identification: 124 133 123 Control Type: Integrated Furnace Control (IFC) Direct Spark Ignition (DSI) Application: Residential gas furnaces and unit heaters utilizing direct spark ignition, integrated blower control, flame sensing, and safety monitoring. Major Components High-Voltage Spark Ignition Transformer Large integrated spark ignition coil provides high-voltage ignition for direct spark ignition (DSI) burner systems. Control Transformer ZETTLER MAGNETICS Model: ZM12-00048 Board-mounted control transformer Made in China Microcontrollers Three onboard control ICs (U1, U2, U3) manage: Spark ignition sequence Gas valve operation Flame sensing Blower operation Safety lockout System diagnostics Power Relays TE Connectivity / Potter & Brumfield T9AV5D12-22 Coil: 22VDC Form C Contacts N.O. 20A @ 240VAC N.C. 10A @ 240VAC TE Connectivity / Potter & Brumfield T9AV1D12-22 Coil: 22VDC Form A Contacts N.O. 30A @ 240VAC GOODSKY RWH-SS-112DMF-U (2) Coil: 12VDC Contacts: 17A @ 31VAC Pilot Duty 1/8 HP @ 240VAC Used for blower and auxiliary output switching. Power Components Large polypropylene film capacitor Four high-power ceramic resistors Multiple electrolytic capacitors Line Voltage Connections Terminal Function UNUSED Reserved Terminal ACB HEAT Air Circulating Blower (Heat) ACB COOL Air Circulating Blower (Cool) WR Output Terminal Power Connections Terminal Function 24VAC HOT 24VAC Control Power GROUND Equipment Ground Sensor Connections Terminal Function FS2 Flame Sensor Provides flame rectification feedback for safe burner operation. Harness Connectors 6-Pin (2×3) White Molex Connector 5-Pin Black Modular Header for low-voltage system harness Compatibility Direct replacement for: 7-405-I HSCI 1840 Commonly found in: Lennox gas furnaces Residential gas unit heaters HSCI direct spark ignition heating systems Compatible with systems featuring: Direct Spark Ignition (DSI) Flame rectification sensing Multi-speed blower motors Standard 24VAC controls ⚠️ Always verify before purchasing: Furnace or unit heater model number Existing part number Connector configuration Wiring layout Board revision Why Buy This Board? ✔️ Genuine OEM HSCI furnace control board ✔️ Fully tested and ready for installation ✔️ Direct Spark Ignition (DSI) control ✔️ Integrated blower and ignition management ✔️ Built-in flame sensing and safety monitoring ✔️ Cost-effective replacement for failed OEM boards Pickup: Toronto / GTA