There may be a number of reasons why your overhead door does that. A built-in safety feature makes the electric opener open the door back up if something is out of the normal to prevent damage or any threats to safety. There are several things you can do to troubleshoot the problem.
Check that the threshold of the overhead door is clear. The opener may sense if there is something blocking it even slightly.
Take a closer look at the photo safety eyes or photo-cells located at the bottom of the tracks. Sometimes if they get hit or misaligned and the infrared beam between them gets disrupted the opener will believe that something is blocking the door. If the small green or red (amber) light on the safety eye is not turned on, it may be a sign of the safety eyes being misaligned and the beam not getting reflected from the other unit. In this case try aligning them with each other until the lights come back on, try then to close the door normally. Often the safety eyes may be fine but the wires connecting them to the opener may be damaged, cut or short-circuited by touching another surface. You can try moving the wire around carefully with your fingers to see if the lights on the safety eyes blink or come back on when you move the wire.  It could be as simple as a cobweb or fly etc interfering with the beam, try to make sure there is no obstruction that may cause the two eyes not to see each other.
The regular travel distance may be hindered. This can sometimes happen if the tracks or hardware of the overhead door get hit or twisted out of place. The opener can believe there is something blocking the overhead door if it is forced to stop before it has moved the programmed travel distance.
Travel limits may be slightly off in the openers limits switch. The limits control the exact spots where the overhead door stops when it is raised or lowered. On residential garage door openers, the limits can be adjusted by turning the limit screws with a flat-head screwdriver. The limit screws are usually located on the side of your opener. On larger commercial openers, setting their limits is a bit more complicated. On some openers the limits can be adjusted by pushing down the brake plate and turning the two white limit cogs to the desired spot on the limit shaft. You will need to open the opener cover and locate the limit shaft in order to do this. It is however highly recommended that a trained service technician does this work as contacting any of the circuitry may cause further expensive damage. There is also a safety risk of electrocution.
The logic board may be malfunctioning. Like any electrical devices the logic board, the central brain in the opener that controls the operation of the overhead door, can get worn out with time. It may also be affected by voltage spikes in the electrical grid or if the proper voltage does not pass through to the opener. Other signs of a faulty logic board may be that the overhead door opens or closes by itself without explanation, even though the door otherwise operates normally.
If your overhead door is still not working properly or you feel uncomfortable troubleshooting or working with your overhead door and opener yourself, please don’t hesitate to call us. Easy Lift Doors expert technicians are more than glad to help and will promptly get your overhead door working properly again.