If you used to use Wi-Fi (wireless LAN) but no longer need to do so due to a change in connection mode and so on, you can disable your Wi-Fi connection.
By removing unnecessary Wi-Fi signals, you can also reduce the load on your standby power.
Turn off the printer if it is on.
Turn the printer on while holding down the 
button.
The default network settings are restored and Wi-Fi connection is disabled.
You need to make network settings to use Wi-Fi again.