If you wish to do a factory reset of your Smart AC Control V3+, touch the main display of the device for at least 5 seconds.
This will open the reset menu and the device will show a screwdriver and wrench symbol.
Use the arrow buttons to cycle through the menu until you see a symbol with an exclamation mark and a trash can.
Touch the main display to reset the device back to factory settings. The exclamation mark and trash can symbol will blink to confirm the successful reset.