York S1-024-35272-000 SPNO Pressure Switch Close On Fall -0.54" WC

York S1-024-35272-000 is an SPNO close-on-fall pressure switch set at –0.54 inches water column, designed to ensure safe airflow and draft control in HVAC systems. The switch functions by sensing pressure changes and closing the normally open contacts when pressure falls to the specified level, confirming proper venting conditions. It is commonly used in York gas furnaces, rooftop units, and heating equipment. Key benefits include reliable airflow verification, enhanced operational safety, accurate pressure monitoring, prevention of system faults, improved heating performance, and long-term durability in demanding HVAC applications.