Garage door openers are usually among the most reliable pieces of equipment in a home, especially considering how much work they perform during their lifetimes. However, there are occasional problems that arise with openers, and that's why it's important for you to know how to make simple repairs and adjustments. One such such problem is a door that begins closing or closes, stops, and reverses into its open position. Below is more information on how to correct the problem and get your garage door opener functioning smoothly:

Closing force and travel limit – their purposes

Most homeowners are familiar with electric eye sensors that detect motion at the garage doorway; these automatically stop garage doors in their paths should an object, person or animal interrupt the invisible beam. However, modern electric garage door openers possess other safety features that help prevent accidental crush injuries. Two of these are the closing force and travel limit mechanisms. Below is a brief explanation of each:

• Closing force mechanism – this consists of an electric switch tripped when a garage door meet a certain amount of resistance while lowering. If the door strikes an object, the resistance feedback from the door is transmitted through the drive mechanism into the opener. There, the closing force switch automatically stops and reverses the door.

• Travel limit mechanism – this adjustable device stops the travel of the garage door when it reaches a certain point in its operation cycle. The travel limit mechanism prevents a door from pushing too hard into the ground or from not closing far enough.

How to adjust the closing force

When the door begins lowering, but instead stops and reverses, you should suspect the closing force is not set properly. Here is how to adjust it:

1. Unplug the garage door opener from its outlet or turn off the breaker switch that provides its power.

2. Take a look at the garage door opener, and locate the closing force adjustment. In many garage door openers, it is a round, slotted knob turned with a flat blade screwdriver. It may lie next to the opening force adjustment; this particular control can be useful if the garage door won't lift for some reason, but it shouldn't be adjusted otherwise.

3. Once you have found the closing force adjustment knob, observe which direction it should be turned to increase the closing force. Turn the knob just a bit, and restore power to the opener.

4. Test your garage door to see if it will close properly. If it doesn't, continue adjusting the closing force knob a little at a time until it works correctly.

5. If you hear loud grinding or screeching noises or see the door binding or stuttering while lowering, then the door may be obstructed or the rails warped. Do not attempt to force the garage door to close by continuing to adjust the closing force mechanism, or you may damage the opener. Contact a qualified door repair or installation specialist for help.

How to adjust the travel limit

When a garage door closes all the way, but immediately begins opening when it reaches the ground, the travel limit mechanism is probably set so it allow too much downward movement. It, too, can be adjusted to prevent this from occurring:

1. Unplug the opener or switch off the appropriate breaker at the panel.

2. Locate the travel limit adjustment; in most instances, it will also be an adjustable knob that can be turned to either increase or decrease the distance the door moves. Look for an arrow or other indicator that shows you which way to turn the knob in order to shorten the door travel distance.

3. Turn the knob a small amount, and restore power to the garage door opener.

4. Test the garage door to see if it stops just after touching the ground. Make additional adjustments if the garage door continues to strike the ground and rebound open.

5. Once you finish making adjustments, look under the door to check for a properly sealed gap. If you see light, you need to turn the travel limit adjustment knob back a bit so it adequately seals the gap between door and the ground.

For assistance, call in a professional garage door repair service.