The Lennox 69W55 2-Stage Pressure Switch is a safety and monitoring component designed for compatible Lennox gas furnaces and HVAC heating systems. It senses pressure changes within the furnace’s combustion or venting system and opens or closes electrical contacts when specific pressure conditions are reached. The two-stage design supports proper operation across different heating dem... https://www.partshnc.com/69w55-lennox-2-stage-pressure-switch