The connection between the probe and the range extender is always established automatically. If the Bluetooth LED does not light up continuously when the probe is charged, place the probe in the charging station and wait until the Bluetooth LED goes out, then remove it again and wait a few seconds. If the Bluetooth LED lights up continuously, the connection is established. The connection between the range extender and the app should ideally be restored automatically, but you may have to initiate the restoration manually.