Before switching from heating to cooling mode, please ensure that your temperature regulation devices are compatible and that you performed all necessary manual actions related to this mode change.
Switching your thermostat from heating to cooling mode is made through your temperature scheduling.
In the Home + Control App, go to the settings and select "Schedules". On the temperature schedule screen, click on the name on top, then select "Cooling" tab. You can now create a new cooling schedule or activate one of your cooling schedules.
Please note that switching from heating to cooling mode applies to all connected thermostats in your home.