Check the breaker controlling the door opener and reset if it it s tripped.
Garage door chain sagging and hitting door.
A loose chain isn t just noisy it also forces your opener to do more work making the whole system less efficient.
If your garage door opener uses a chain drive then it is probably like a lot of other garage doors.
Garage door chains become slack from everyday use because of the vibrations created by the motor and the weight of the door.
While many problems that keep the door from opening are caused by broken springs a lot of other parts could be keeping your door from functioning properly.
Overall this gives the opener less power to open and close the door.
The solution to this is to push the door outward from the lower hinge therefore squaring it up and stopping the sagging.
If the bottom of your door below where the lock and door handle are located is hitting or rubbing the bottom of the door frame then you need to add a cardboard shim to the very bottom and possibly the middle hinge also.
This page should help you troubleshoot your garage door problems.
There may be an adjustment linked to the chain or an adjustment to the length of the door opener track.
One of the more difficult problems for do it yourselfers to diagnose is a worn cable pulley on an extension spring door.
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.
Thankfully garage door manufacturers have included a part in their designs that can help you tighten your chain and stop the chain from slapping against the rail as it opens and closes your garage.
Over time the drive chain can loosen and create slack.
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.
Both adjustment types should be done with the door closed and disconnected from the opener using the emergency release.
Tightening up the chain is therefore an important part of regular maintenance.