What is the Auto Changeover feature and how do I use it?

Auto Changeover is a feature for climates where both heating and air conditioning are used on the same day, allowing the thermostat to automatically switch between heating and cooling based on indoor temperature. The Auto setting only appears if it has been set up by your heating and air conditioning dealer. When in Auto mode, the thermostat automatically keeps the cool and heat temperature settings three degrees apart (called deadband), and this three-degree deadband is not adjustable. (Page 15)