Bosch BCC100 Quick Start Manual page 15

Auto Reconnect
If your device loses connection with your wireless network,
it will automatically attempt to reconnect after five
minutes. If that fails, it will make a new attempt every 15
minutes for the next 24 hours. Any manual network
reconfiguration of the thermostat will stop automatic
reconnection attempts.
Wi-Fi can be manually turned off or on. Turning off your
Wi-Fi will also disable the internet connection and all
smart features, including App access to the device.