If your garage door won't close unless you keep the button held down, there could be a problem with the sensors. Usually, your door goes down when you hit the button once. But if you do that and the door goes down a bit then goes back up, it's an indication the safety feature is kicking in. Before you call a repair company to fix the door, there are a couple of things you can check first.
Find The Sensors
Look along the garage door track near the floor, and you'll see a sensor. There is one on each side. One sends a signal and the other one sees it. Therefore, they have to be in alignment for this process to take place. If one of the sensors is kicked or bumped out of place, it will affect the operation of your door. The sensors have indicator lights, which make it easy to tell if they are in alignment.
Check The Lights
There should be a tiny green or red light on the side of the sensor. If the light is flickering, it's a sign the sensors are out of alignment. All you have to do is reposition one of the sensors until the light stops flickering. When lights on both sensors are shining steadily, it indicates they are aimed properly, so if your garage door still doesn't close properly, you'll need to call for professional repair.
Check The Connections
The lights might flicker if there is a problem with the wiring too. If that's the case, then realigning the beam won't make the flickering go away. Wiring problems can even cause the light to go out. Some sensors have wires that plug into the case. Check that the connections are tight. Other wires are screwed into the electrical components. If one has come loose, be sure to turn out the power before you try to fix it. In addition to wiring problems, the circuitry inside the sensor could be bad. If one of the sensors fails, call a garage door company to check it and install a new one if necessary.
Clean The Lens
If the wiring seems intact, and you can't get the flickering to stop by repositioning the sensors, try cleaning the lenses. There might be a piece of dirt or leaf debris covering the lens enough to break the beam. Wipe the lenses off with a cloth and see if the flickering stops. Keep in mind you may have knocked the lenses out of alignment by cleaning them, so reposition them once more.
Fixing problems with a sensor is one of the easiest garage door repairs you can make. It is also one of the few you can do without having to call a contractor, unless the electrical components are damaged—in which case you should leave the work to a professional, such as All Pro Quality Garage Doors, Inc. It's easy to overlook the small things, so don't forget to check both sensors when your garage door won't close.