Your wall switch may be in child proof mode. When this is set, only the arrows will have functionality. The appliance can enter child proof mode when the fireplace is on or off.
To exit child proof mode: Press the Up Arrow Button twice and Down Arrow Button once. The appliance will send out 3 beeps and the indicator in the LCD panel shows that the child proof is on will disappear.
To enter child proof mode: Press the Up Arrow Button twice and Down Arrow Button once. The unit will send out 3 beeps and an indicator in the LCD panel will show that the child proof is on.