How to Align Your Garage Door Sensors in Under 30 Minutes
Get your garage door back on track
- Electricity-resistant gloves
- Screwdriver
- Level
- String
The sensors on your garage door opener are one of the things you probably don’t think about—until it stops working. A small misalignment can turn your peaceful day into a frustrating one, with the risk of damaging your freshly detailed car or, worse, causing injury. If your garage door refuses to close or slams down on anything in its way, misaligned sensors could be the problem. Luckily, fixing them is easier than you think. Follow these nine simple steps to get your sensors back in line so you can stop worrying about your garage door coming in like a wrecking ball.
Turn Off the Power to the Sensors
Photo: Gregory_DUBUS / iStock / Getty Images Plus / Getty ImagesBefore you start fiddling with your garage door opener and its sensors, turn off the power. If they’re plugged into a wall outlet, just unplug them. If not, head to your breaker box and trip the fuse to the whole garage. Don’t worry—you’re not getting up close and personal with any live wires here, but it’s always wise to wear electricity-resistant gloves, just in case. A little precaution goes a long way, and it’s always better to play it safe with electricity.
Loosen the Screws on the Mounting Bracket
Next, grab your screwdriver and loosen the screws on the mounting bracket for each sensor. Don’t go too far—you’re not removing them entirely. Loosen them enough so the sensors can move up and down. The goal is to give them enough room to shift when you want to move them without them being so loose that they move on their own.
Slide the Sensors Down
Photo: BanksPhotos / iStock / Getty Images Plus / Getty ImagesSlide your garage door sensors down. Move them as low as possible without the screws popping out. You want them to be at their lowest point while still securely in the brackets. And you should opt for a "hands only" rule here. You may be tempted to use another tool to tap and shift it into place, but experts would suggest otherwise. Tools can scratch or damage the sensors, and you don’t want that. At this point, all you need is an alignment, not a replacement. Just give the sensors a gentle nudge into place.
Tie a String Between the Sensors
Grab and cut a string that’s a few inches longer than your garage door opening. Tie one end to the first sensor and bracket. Make sure it’s tight. Then, stretch the string across to the second sensor so it runs right through the center. Tie it off so the string sits exactly across the middle of that sensor. This will be your guide to make sure both sensors are aligned.
Check the String with a Level
Photo: BonNontawat / iStock / Getty Images Plus / Getty ImagesHold a level along the string to check if it’s straight. Read the level by making sure the bubble is centered between the lines. If it’s off, slide the sensor brackets up a bit to adjust them. This might take a couple of tries to get it right. And if you get tired of the back-and-forth, now’s a good time to bring in help so they can handle the leveling on one side as you handle the other. While you can definitely handle this project on your own, a helping hand can make the process go a lot smoother and faster.
Tighten the Mounting Bracket Screws
Now that your sensors are lined up, tighten the screws. Secure them enough so that the sensors stay put when you try to move them. If they don’t budge, move on.
Double Check the String and Sensors
After tightening the screws, double-check that the string and sensors are still level. Tightening the screws can sometimes mess with the alignment, and you don’t want the sensors shifting. If they’re off, realign them. Remember—the infrared beam has to stay perfectly straight to work.
Turn On the Power to the Sensors
Remove the string and turn the power back on.
Test the Sensors
Photo: mirsad / Adobe StockOnce everything is back on, test your sensors. Grab something safe—like a broomstick—and carefully place the bottom between the sensors. If the door doesn’t close, your sensors are properly aligned. If it does, restart the process or bring in a professional.
When to Align Your Garage Door Sensors
You should align your garage door sensors when you notice that the door either won’t close or tries to close despite an obstruction. If the door opens but refuses to close, it could be misreading the sensor’s signal as if something’s blocking its path. On the other hand, if the door starts closing with an obstruction in the way, that’s another sign that it’s time for alignment.
Check for indicator lights—each sensor has one. You’ll need to check your manufacturer’s guide for the exact light color codes, but a blinking light typically means something’s off. You should also inspect the sensor lenses for dirt. A buildup of dirt can confuse the sensors into thinking they’re misaligned. Also, damaged wires can cause alignment issues, and if left unfixed, could eventually stop the sensors from working altogether.
If you spot a red light or the alignment seems perfect, but the door still acts up, it’s probably time to call in a professional. The sensors might be faulty, and instead of alignment, you may need a replacement to get everything working again.
DIY vs. Hiring a Pro
Aligning your garage door sensors is definitely something you can handle as a DIY project, especially if you’re just working with some basic tools and a little patience. However, keep in mind that a malfunctioning garage door can be dangerous. If your door stays open, it leaves your home and other valuables vulnerable. If it closes on an obstruction, you risk damaging your car—or worse, injuring someone. So, if you’re not confident or comfortable with the process, consider hiring a garage door professional. They can get the job done in under an hour, and on average, it’ll cost you around $40 to $110 per hour for the fix. While it’s more than you could expect to pay to DIY, it’s worth the peace of mind.
Garage door sensors work by using infrared beams to detect objects in the door’s path. One sensor sends a beam while the other receives it. When the beam is broken—say, by your car or anything else—the sensors signal the door to stop or reverse. It’s all about safety and making sure nothing gets trapped under the door. If they’re misaligned, the beam doesn’t connect, and the garage door might stay open or close regardless of obstructions.
Garage door sensors should be installed on each side of the door, typically six inches off of the ground. The sensors communicate through an infrared beam, so they need to face each other directly for the system to work properly. Make sure they’re level and aligned, and keep the area around them clear. If they’re too high or out of alignment, your garage door won’t function properly.
The lights on your garage door sensors can vary depending on the manufacturer, so check your manual for exact details. Generally, garage door sensors will have green, red, and yellow or orange lights. A solid green light usually means the sensors are aligned and working properly. A red or blinking light indicates misalignment or an obstruction in the path. Some models also show a yellow or orange light when there’s a weak signal. While the colors are pretty standard, always confirm with your manufacturer to be sure.
If you open your garage manually, you don’t need sensors. If you have an automatic garage door opener, sensors are required by law. The federal law UL 325 mandates that all residential garage door openers in the U.S. must include sensors. Designed to prevent accidents and reduce the risk of entrapment, the sensors should be able to reverse the motion of the garage door within two seconds of detecting an obstruction. The sensors are there to keep you, your family, and your belongings safe from a door that might otherwise come down too hard or too fast.
