When your liftmaster garage door opener opens and closes by itself here are the troubleshooting tips you need to follow.
Garage door opener sensor trouble shoot.
Raise the garage door using the control button on the garage wall or the remote control unit from a vehicle.
If one or both sensor lights won t come on check the led troubleshooting light on the motor unit for an error code.
The main drive gear is the plastic gear that comes in direct contact with the worm drive gear on the motor.
Replace the main gear drive if the garage door opener makes a grinding noise but the door doesn t move your main drive gear is probably toast.
Find error code on motor unit.
Ensure that the wires are properly connected and not loose at both connection sites.
This is not a common problem at all but it could happen.
If none of these troubleshooting options work look at the garage door sensor s manual and see if there is anything in it that can help you to fix the issue.
Disconnect the control station.
Remove the bell wire from the single button control station s terminals and operate the garage door opener from the remotes.
Inspect each sensor to make sure the green or red power indicator lights are illuminated.
Your final option is to get in touch with a garage door expert to fix the problem for you.
Garage door opener won t open all the way fix.