How To Fix A Garage Door Sensor Yourself

Whether you're heading out for your morning commute or parking your car after an afternoon of leisurely driving, finding out that your garage door has stopped working is a surefire way to ruin your day. Before you call a repair person and sink a couple hundred dollars into their service, though, take a step back and cool off. This may actually be a problem you can safely, cheaply, and easily fix yourself. If the door attempts to open or close and fails, or if the garage door's overhead light blinks at you repeatedly when you try to open the door, it's likely that you have a sensor issue on your hands. Luckily, DIYers can attempt to fix these sensor issues themselves with safety and certainty on their side – unlike some car parts.

Thankfully, fixing a sensor issue on your garage door tends to be straightforward. Most of the time, you'll just need to clean the sensors to ensure no debris is blocking the infrared signal passing between the sides of your garage door. If you're dealing with a misalignment, you might need to realign the sensor units so the photo eyes can see one another. Occasionally, on older garage door opener models, one sensor could simply be getting too much sun, which interferes with the infrared light. This can be remedied by swapping both sensors' positions, but you shouldn't run into this particular issue as often as the others. In any case, fixing the door is easy and quick, so you can stop sweating and get on with your day in peace. The following steps should be enough to get your problem sorted lickety-split.

Once you've confirmed that you're dealing with a sensor issue, the first step is to disconnect the power from your system. Doing so prevents you or others from mistakenly activating the door while you're working. It also allows you to perform your next step — cleaning the sensors — without risking damage to the internal electronics.

Each sensor for a garage door sends out a beam of invisible light, which the other sensor detects. When both sensors are detecting the other sensor's light, the system knows the door is unobstructed and safe to open or close. Over time, the sensors on either side of your garage door will inevitably collect dirt, dust, cobwebs, and debris. When too much junk builds up over the sensor's eye, it disrupts the sensor's ability to send and receive signals, making the sensor report an obstruction.

To clean your sensors, you can simply wipe them off with a cloth or paper towel. If the buildup is too heavy, you may need to wet the cloth or use something like isopropyl alcohol to get the lens clear. The process is similar to how you might maintain your car's backup camera, which is something else you should be doing often. One the lens is clear, don't introduce power to the unit until any liquid has fully evaporated. (And make sure track for the door is clean, too — it might be causing issues if you've greased it in the past.)

If your sensors aren't dirty, or if cleaning them doesn't solve the problem, you're likely dealing with misalignment. Just like with how dust can block one sensor's infrared beam from being detected, misaligned sensors will fail to reach each other with those beams. Sensors may get knocked out of alignment on accident, or the vibrations from the door opening and closing can slowly shift one out of place until it eventually can't communicate with its counterpart.

Ensure that both sensors are pointing as directly at each other as possible. There's some room for error here, so you likely won't need to break out your level tool or do any precise measurements. Typically, you can adjust your sensors by loosening any mounting screws holding them up, adjusting the sensor, and then tightening the screws back down. It's just as simple as it sounds and should only take a handful of minutes to complete.

Once you're done, power the system on and test it out. Ensure that the sensors' indicator lights are glowing steadily and not blinking. Typically, the one light will be green and the other will be amber or red to indicate that everything is functioning properly, but the exact colors might vary depending on your sensor model. Regardless of color, solid lights are generally a good sign, and blinking lights (or no lights at all) mean something's up.