Lennox 57W79 Pressure Switch 0.70" WC Green

The Lennox 57W79 Green Pressure Switch is a control component that is used to detect the difference in air or gas pressure in HVAC systems and activate at about 0.70 inches of water column. It opens or closes an electrical circuit when the pressure measured reaches the set point, and before the system moves to the next step, it must have an appropriate amount of air flowing or the inducer must be running. This switch is installed in furnaces, air handlers and combustion air systems to ensure proper venting and blower operation.