The terminals are usually marked: "C" for Common

This orange replacement spring is precision-engineered to provide an outlet pressure range of 4-8" W

using it with higher-pressure refrigerants like R-410A will result in incorrect trip points and potential system damage

Designed for high-cycle reliability in demanding HVAC environments

Precise Fan Delay: Correct 1-20 second ON delay ensures the heat exchanger is primed before air distribution begins

Lennox 49L90 Pressure Switch The terminals are usually marked:Ensure reliable combustion safety and system performance with the Lennox 49L90 Pressure Switch. This genuine OEM component, which is a direct replacement for Lennox 49L9001 and Honeywell IS20100 3072, is engineered specifically for Lennox furnace pressure switch applications requiring a precise . 47" WC (water column) trip point. Featuring a 1 4" barb connection for secure pneumatic hosing and a single pole single throw (SPST) configuration, this