LG MH8082X Owner's Manual page 7

Your oven has a safety feature that
prevents accidental running of the oven.
Once the child lock is set, you will be
unable to use any functions and no
cooking can take place.
However your child can still open the
oven door.
Press STOP/CLEAR.
Press and hold STOP/CLEAR until "L" appears on the display and BEEP
sounds.
The CHILD LOCK is now set.
The time will disappear on the display but will reappear on the display
a few seconds later.
If any button is pressed, "L" will appear on the display.
To cancel CHILD LOCK press and hold STOP/CLEAR until "L" disappears.
You will hear BEEP when it's released.
7
Child
Lock