Lennox 56K85 Control Board

The Lennox 56K85 is a critical Integrated Modular Control (IMC) board designed specifically for managing the secondary gas valve in multi-stage heating systems. This OEM Lennox replacement board (part number 56K85) serves as the Gas Vlv #2 control module, ensuring precise sequencing and timing for combustion cycles in heavy-duty commercial rooftop units and high-capacity furnaces. Built to withstand the thermal stresses of the cabinet environment, the 56K85 circuit board communicates directly with the primary IMC controller to regulate dual-stage heating demands efficiency. For contractors troubleshooting ignition failure or erratic gas valve operation, verifying the diagnostic LED codes on this module is essential for determining communication link integrity. Replacing a faulty Lennox HVAC control board with this genuine factory component ensures the system maintains its original engineering specifications for safety and air-fuel ratio management without requiring field-level modifications to the wiring harness.

• Direct OEM Compatibility: Engineered as a drop-in replacement for Lennox Gas Vlv #2 control systems, ensuring physical fit and electrical alignment.
• Precise Multi-Stage Logic: Manages secondary burner sequences to maintain optimal heating output during peak demand.
• Durable Construction: High-grade traces and solder joints designed to resist vibration and moisture-related failures common in HVACR environments.
• Simplified Troubleshooting: Integrates with existing Lennox IMC diagnostic protocols for rapid fault isolation in the field.

Does this board control the primary gas valve?
No, the Lennox 56K85 is specifically designated as the Gas Vlv #2 IMC module. It handles the secondary stage of heating, working in tandem with the primary ignition control.

Can I use this module on other non-Lennox equipment?
This is an OEM Lennox part calibrated for specific sequences within their Integrated Modular Control architecture. Use only in compatible Lennox-branded commercial or residential systems.

What are the signs of a failing 56K85 board?
Common symptoms include the second-stage heat failing to energize, intermittent dropouts during high-fire operation, or communication error codes appearing on the main IMC display.

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.