This specific outer window is primarily designed for PC-3D and PC-4D systems

Advanced System Efficiency: Eliminates the need for external mechanical thermostats or bulky dual fuel kits by using integrated panel logic

High-Flow Efficiency: The large 2-5/8" port minimizes suction line pressure drop

This Lennox furnace limit switch prevents thermal stress on the heat exchanger and ensures the blower assembly is functioning within safe operational parameters

Industrial Durability: Rated for high-heat applications in both residential and commercial gas-fired equipment

Lennox 14M89 Tubing Kit 326058-758 This specific outer window isThe Lennox 14M89 Pressure Switch Tubing Kit is a critical replacement component designed for precise pressure monitoring within high efficiency Lennox furnace systems. This kit features high grade, flexible silicone tubing engineered to resist heat and maintain structural integrity under constant vacuum and positive pressure cycles. Proper furnace pressure switch calibration relies on the airtight fit provided by these OEM spec connectors, preventing