The Rheem–Ruud RETST800SYS econet thermostat 800 Series Smart Thermostat is an innovative, user-friendly gadget that provides accurate climate management in HVAC systems. This smart thermostat operates at a voltage of 24V and interacts smoothly with modern heating and cooling systems, providing increased control and convenience. https://www.partshnc.com/retst800sys-rheem-ruud-econet-800-smart-thermostat