Your products may not automatically appear in the Apple Home app after setup is complete. For example, this may be the case if your products were originally set up using a friend or family member’s account or on an Android smartphone. Go to the Home + Control app settings and select “Manage My Home,” select the room the thermostat is installed in, select the thermostat, and then select “HomeKit & Siri.” Follow the instructions in the app to set up the thermostat with HomeKit.