Lennox 73W33 Dual Stage Pressure Switch 0.68/0.35 WC

The Lennox 73W33 is a dual-stage pressure switch designed for use in Lennox residential and light commercial HVAC systems. This OEM replacement component monitors combustion air pressure to ensure safe furnace operation by verifying proper draft conditions before and during burner ignition.

Key Specifications:

• Pressure settings: 0.68" WC (close on rise) / 0.35" WC (open on fall)
• Dual-stage operation for multi-stage furnaces
• Genuine Lennox OEM part ensures proper fit and function
• Safety control device that prevents furnace operation under unsafe draft conditions
• Direct replacement for original equipment

This pressure switch is a critical safety component that must be replaced with the exact OEM specification. The dual pressure settings allow it to monitor both low-fire and high-fire stages in compatible two-stage furnace models. When proper draft pressure is not detected, the switch prevents the furnace from operating, protecting against potential combustion safety issues.