Lennox 68M64 Control Board

The Lennox 68M64 Control Board is a specialized integrated furnace control designed for precise regulation of residential and commercial HVAC systems. This OEM replacement part is technically identical to the Lennox 68M6401, providing a direct drop-in solution for contractors servicing Lennox furnaces and heat pump systems. Engineered to handle 24V AC input, this printed circuit board (PCB) manages critical blower motor timing, defrost cycles, and ignition sequences. By interpreting signals from the thermostat and active sensors, it optimizes system efficiency and maintains stable cabin temperatures. The board features an integrated diagnostic LED to streamline HVAC troubleshooting, allowing technicians to quickly identify fault codes like ignition failure or limit switch trips. Built for durability in high-cycle environments, it ensures the reliable operation of the inducer motor and gas valve. Always verify the wiring schematic on the furnace access door to confirm terminal identification before completing the swap.

• Universal compatibility as a direct 1:1 replacement for the 68M6401 model.
• Enhanced system diagnostics via on-board LED flash codes for faster field repairs.
• Robust 24V control logic manages blower delay and ignition safety protocols efficiently.
• Genuine OEM construction ensures correct mounting hole alignment and electrical pin-out matches.

Is the 68M64 cross-compatible with older Lennox part numbers?
Yes, the 68M64 is the direct successor and is technically identical to the 68M6401. It is commonly used in both gas furnaces and heat pump air handlers as a primary ignition control.

How do I troubleshoot a suspected board failure?
Verify line voltage (120V) at the input and low voltage (24V) at the transformer. If the diagnostic light is inactive despite proper power supply, or if the board fails to energize the blower motor or igniter during the sequence of operation, a replacement is likely required.

What safety precautions are necessary for installation?
Disconnect all power sources before handling. Use a multimeter to confirm the circuit is dead. Ensure proper grounding and follow the wiring diagram precisely to prevent short circuits or component damage.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.