How come the garage door comes down but goes right back up once it gets to the concrete floor?

expert EXPERT January 30, 2008

The most likely reason is that your lower travel limit needs adjusting. Your door may have settled or shifted due to age and weather changes and now contacts the floor before the lower limit switch is triggered. The opener sees that as the door not being able to close completely and, since that could be caused by something or someone trapped under the door, it reversed the door back to the open position as a safety precaution.

If the door only does this with the remote and you need to hold the wall switch button continuously to bring the door down then there could be a problem with the safety sensors near the bottom of the garage door itself. Again, the opener would see a problem there as a potential safety concern and re-open the door. Typically, however, a safety sensor issue will cause the remotes not to work at all and will reverse the door long before it reaches the floor. And any problem with the safety sensors should also trigger flashing of the overhead light.

Your owner's manual and the links below have more information that should help locate and resolve the issue.