You should inspect your garage door at least once a year to make sure that there aren’t any worn or loose parts. Clean the rollers, pulleys, and cables; lubricate them with light oil. Also, spray or wipe a Teflon lubricant to the weatherstripping where it contacts the door.

The two extension springs that counterbalance the door’s weight should hold the door steady in a half-open position. If you want to increase the tension, you will need to shorten the lifting cable. You should NEVER service a torsion spring (the large horizontal spring above the door) without an expert there. It is very dangerous.

If the door is operating properly, it should reverse if it hits something. However, if the opener was made prior to 1982, they do not have a backup to this system; so they should be replaced.  Since 1993 all openers have to include a monitored backup system. It is a sensor that passes a light beam across the door opening. What happens is once the beam is interrupted the door will reverse, and if the beam sensor is unplugged the door will not operate. You cannot bypass the beam sensor.