Garage door chains become slack from everyday use because of the vibrations created by the motor and the weight of the door.
Garage door chain loose when closed.
If that point is more than four feet or less than three feet above the ground you will need to balance the door.
If you find that your garage door opener chain has become loose with time you may want to tighten it up in order to remove some of that slack.
Tightening up the slack on your garage door will allow it to run more efficiently and will prevent loud noises that disrupt your home.
Tightening up the chain is therefore an important part of regular maintenance.
Move the garage door up and down until you find a place where the door stays suspended when you let go.
You may find that a loose garage door opener chain has less power to open and close your garage door or you may find that it is just hitting the door as it moves it and creating an annoying sound.