If you’ve ever had your garage door mysteriously refuse to close, it could be a safety feature working overtime—but not correctly. Most current garage doors are protected by photo sensors that prevent the door from closing if the beam between the sensors is interrupted. This prevents the door from closing and injuring anyone (especially children or pets) who may be in the path of the door, and can also avoid damage when objects (such as toys, tools, or even vehicles) obstruct the opening.
However, because the sensors require precise alignment to complete the light beam that is core to the whole system, a misalignment can prevent your garage door from closing at all. Here’s how you can fix the problem.
Inspect the Sensor(s)
Before getting into a larger project, a little inspection can determine if the a minor adjustment will do the trick.
Check to see if the sensors have LED lights are on. If one has a lit LED while the other is flickering or entirely off, you may be able to manually adjust the unlit sensor so that it lines up again (which will result in both lights remaining lit). Then you’re back in business.
Also check to see if the lens on one or both is dirty. Gently clear the debris, taking care not to bump them out of alignment, and see if that solves the problem.
If neither of these adjustments work, then you can continue, aligning the sensors from scratch.
Cut the Power
Even though this isn’t exactly an electrical project, it’s always safest to turn off the power at the breaker box just to be sure that the door opener can’t be triggered. You don’t want to accidentally activate the door while you’re working, nor do you want anyone leaving or returning home to press the remote out of habit and cause potential problems or even injury.
Loosen the Sensors
Using a screwdriver, loosen the screws that hold the sensors in each of the mounting brackets. Don’t fully remove the sensors, or loosen too much. You should be able to move the sensors, but only with intentional repositioning. They shouldn’t slide on their own.
Reposition the Sensors and Level
Slide the sensors on each side of the door downward as far as they’ll go (without unscrewing the sensor mounting bracket). Tie a string (long enough to span the width of the garage door) around the bracket on one side so that the string will line up with the sensor lens. Pull the string taut and tie to the other bracket in the same position. Using a level, check that the string is level. If not, adjust one or both of the sensors to bring the string up to level.
Tighten the screws to fasten the sensors into their newly aligned position. Afterward, verify that the string stayed level, and didn’t move as you tightened the screws. If everything looks good to go, remove the string, turn the power back on, and close the garage door!
If you run into any problems during this process, or discover a maintenance issue best left to the pros, give us a call. The Overhead Door Depot is here for your maintenance, repair, and installation needs, with 24/7 emergency service available.