Here s a rundown of some of the possible reasons this can be happening.
Garage door closes then opens liftmaster.
Always keep garage door in sight until completely closed.
Now press the remote control.
As is the case with so many issues at the home there s no one reason why your garage door closes then opens.
Try opening the garage door with the remote and see what happens.
Your travel down setting needs to be adjusted.
The simple stuff if the garage door connected to your liftmaster opener only opens part of the way or it begins to open but then reverses check the track and the surrounding area for any objects.
The force setting tells the opener how much resistance the door should provide and if the opener detects more than is allowed the door will reverse.
The opener s force setting may not be set correctly.
Years ago garage door openers were required to utilize safety sensors to prevent doors from closing on small children.
Make sure the small light on each sensor is lit and not flickering.
Liftmaster uses the protector system which projects an invisible light beam across the door opening and automatically opens the door if something someone crosses it s path.
Close the garage door with the opener and watch it closely as it closes.
These steps should fix most doors.
Your garage door is programmed to travel a certain distance before it closes.
Anytime the main light flashes 10 times and the door reverses to the open position it is a door sensor problem.
To reconnect the garage door to your liftmaster garage door opener manually close the garage door pull the emergency release handle down.
If the garage door does not close completely or begins to close and then opens back up again the down limit switch needs.
This will cause the trolley to move into position and reconnect to the garage door.
Never permit anyone to cross path of moving door.