In order to reset the Smappee Pro/Plus monitor, find the small opening on the right side of the monitor, next to the first 3 CT inputs.
Keep pressing the small button in the opening for about 15 seconds. Use a sharp pointed object such as a pen or a toothpick.
While pressing the button, the LED in the monitor will show different colors. Keep pressing the button until you see a fix blue LED. Once you see the blue LED, you can release the button.
The monitor will now restart. Wait until you see the LED blinking blue (if you install the monitor via Wi-Fi or 3G/4G, the monitor is now completely reset. Wait for a green fix LED if you want to install the monitor with a wired (Ethernet) connection.
To re-install the Smappee monitor, go to the monitor's location in the mobile app and select "settings", "Your Smappee monitors", select the Smappee serial number and the choose "repeat installation".
You can also create a new location in the mobile app and start the installation process.