A programmable thermostat is a device that is installed along with your HVAC unit to adjust the temperature according to a series of programmed settings that take effect at different times of the day. Save Money and Increase your Home's Efficiency One of the great things about a programmable thermostat is that it can save you money. You can program it during times when your family is not home, during the night, or when you are away on vacation. By installing a programmable th