Lennox 11U71 High Altitude Pressure Switch .85″

Description

The Lennox 11U71 is an OEM high altitude pressure switch engineered for use in Lennox furnaces and heating systems installed at elevated locations where air density and combustion conditions differ from sea level. Operating at a set point of .85″ W.C. (water column), this pressure switch monitors the negative pressure generated by the inducer motor to verify proper venting and combustion airflow before allowing the burners to fire — a critical safety function in high-altitude applications.

Key Features

• OEM Lennox replacement pressure switch — direct-fit for compatible Lennox furnace models
• Set point: .85″ W.C. (water column) — calibrated for high-altitude operation
• Monitors inducer/draft pressure to confirm safe venting conditions before ignition
• Prevents burner operation if adequate draft pressure is not established
• Designed to maintain reliable performance in lower air-density environments
• Helps protect heat exchanger integrity and ensures proper combustion efficiency

Application

This pressure switch is specifically designed for Lennox furnaces operating at high altitudes where reduced atmospheric pressure requires a recalibrated switch set point. Installing the correct high-altitude pressure switch is essential for safe furnace operation, proper venting, and code compliance in elevated installations.

Why Choose the Lennox 11U71?

Using the correct OEM-specified pressure switch ensures your Lennox furnace operates within manufacturer safety parameters. The 11U71 provides the precise .85″ W.C. trip point required for high-altitude environments, protecting both the equipment and the occupants it serves.