Lennox 24W49 101021-04 Pressure Switch 0.70/1.05

The Lennox 24W49 (also known by part number 101021-04) is a vital safety and efficiency component for your HVAC system. It functions as a 2-stage pressure switch, specifically designed for Lennox equipment. Here's how it works: The switch monitors the air pressure within the system. When pressure reaches a preset low limit (0.70 in this case, measured in units likely referring to water column), the switch triggers a signal to the furnace or air conditioner to activate the first stage of operation. As demand increases and pressure rises, upon reaching the high limit (1.05 units), the switch signals the system to engage its second stage, providing a boost in heating or cooling power.