How does my Amazon Echo work with Auto mode?

If you use Auto mode, you can still ask Alexa to change the temperature by saying, “Alexa, set (Thermostat Name) to x degrees”.  Alexa will respond to you by saying, “Thermostat in Auto Mode. Aiming for x degrees.” Your ecobee will then use this temperature as the midpoint between your heat and cool set points (based on what you’ve set your minimum heat / cool temperature delta to).

For example, if you’re in Auto mode and you ask Alexa to set the temperature to 22C (72F) and you have your minimum heat / cool temperature delta set to 3C (4F), your heat set point will become 20.5C (22 – 1.5) (70F) and your cool set point will become 23.5C (22 + 1.5) (74F).