You can prevent children or others from using it carelessly.
Press and hold the J and Fan Speed simultaneously for about 3 seconds.
Whenever you press any button on display panel, it will immediately display [L, which means display panel is locked.
All the button on the indoor unit display panel will not work. But the button on the remote controller will be operated.
If you want to cancel the child lock function, press and hold the J and Fan Speed button simultaneously for about 3 seconds again. The unit will respond with beep.