The Lochinvar & A.O. Smith 100166256 SPDT Pressure Switch is a reliable safety control device designed to monitor system pressure in HVAC and water heating equipment. It works by detecting pressure changes and opening or closing electrical contacts when preset pressure levels are reached, ensuring safe and efficient operation. Commonly used in boilers, water heaters, and hydronic heat... https://www.partshnc.com/spdt-pressure-switch-11