While electronic garage doors are a convenience, they are also dangerous. To help prevent injuries, they have sensors and fail-safe options. These systems can lead to garage doors not completely closing. Here are the main reasons your garage door isn't closing the whole way and what you can do about them.
Check the Sensor Lights
Most garage doors will have sensors on either side of the door. All sensors should have lights that are always on. When they're not or when one is blinking, the lines between the sensors aren't aligned properly. This tells the door that something is in the way and the door needs to stop moving.
You'll need to align the lights again. You can usually do this yourself by loosening the knob and pushing it against the metal bracket. It's aligned when the light turns back on. Tighten the knob again and try your garage door. It should close all the way.
Dust and pollen may get into the sensors, especially if you have the door open a lot throughout the day. Make sure you clean the sensors now and then to rectify this option.
Check for Small Objects
Small objects in the garage door's path will alert the system that there is a crushing possibility. The door will stop part way to prevent injury, even if the items are nothing a human would worry about. Look out for smaller objects in the garage door's path, such as small toys and garbage.
You may find that the door closes partway and then reverses back up. This is another sign that something is in its path and it is the safety mechanism kicking in.
Check the Transmitter Batteries
The transmitter for the door will usually have a battery to power it, unless it is connected to the mains. The problem could be something as simple as the battery running out of juice. Change this and check again.
There may be other batteries within the system. Chances are all the batteries were placed at the same time, so you'll need to check them all to make sure the others are working.
Check the Door's Alignment
Finally, check for the alignment in the door. If it is closing slanted, it won't be able to close all the way down. You'll need to improve the alignment of the door, so you can get it working properly. This may not be a job that you want to do yourself, as it can be time-consuming and dangerous.
Take your time to check the small elements before working on the door alignment. Most of the time it is the slightest problem causing the door to only close partway. Contact a company like AAA Garage Door, Inc. for more information.