Garage Door Safety Sensors Out of Alignment
If your garage door won't close all the way and reverses back up, your safety sensors are almost certainly out of alignment. Those two little eyes near the bottom of the tracks have to point straight at each other; when they're knocked crooked or blocked, the opener thinks something is in the doorway and refuses to close. In most cases you can fix it yourself in about 10 minutes by clearing the path, wiping the lenses clean, and gently nudging the sensors until both indicator lights glow solid.
Step by step
-
1
Confirm it's really the sensors
Look at the two photo-eye sensors mounted about 4 to 6 inches off the floor on each side of the door, near the bottom of the tracks. Each one has a small LED. Typically one light is solid (that's the sending eye) and the other blinks or goes dark when alignment is off. If you press the wall button or remote and the door starts down, then stops and rolls back up, the opener is getting a 'blocked beam' signal. That's your sign the sensors are misaligned, dirty, or obstructed, not a motor or spring problem.
-
2
Clear and clean before you adjust
First, move anything out of the beam's path, even a leaf, a trash can lid, a bike pedal, or a cobweb can break it. Then gently wipe each sensor lens with a clean, dry microfiber cloth or a slightly damp one. Sun glare hitting a lens directly can also fake a misalignment, so check if morning or afternoon light is shining straight into an eye. A surprising number of 'broken' sensors are just dirty or sun-blinded.
-
3
Eyeball the alignment and look at the lights
The two sensors must point directly at each other at the exact same height. If one is drooping, tilted, or has been bumped by a car or kid's bike, the beam misses. Watch the indicator LEDs as your guide: when both lights are steady and solid (no flicker), the eyes are talking to each other. A blinking or dark light means you're not lined up yet.
-
4
Loosen, nudge, and re-tighten
Most sensors sit in a bracket held by a single wing nut or screw. Loosen it just enough that you can pivot the sensor by hand, then slowly tilt and swivel it until the partner light turns solid. Snug the wing nut back down gently by hand, over-tightening can knock it right back out of line. Re-check that both lights are still solid after tightening.
-
5
Check the wiring if lights stay dark
If an LED is completely off (not even blinking), the sensor may be losing power. Follow the thin wires from each sensor up toward the opener and look for staples pinching the wire, chew marks, corrosion, or a wire pulled loose from its terminal. Gently reseat any loose connections. A sensor with a dead light usually means a wiring break, not an alignment issue.
-
6
Test the door a few times
Run the door up and down two or three full cycles from both the wall button and the remote. It should close smoothly without reversing. As a final safety check, press the close button and wave a broom handle through the beam, the door should immediately stop and reverse. If it does, your sensors are working exactly as they should.
When to call a pro
Call a pro if the sensor lights stay dark after you've reseated the wiring, if the door still reverses with both lights solid and the path clear, or if you find damaged wiring, a cracked sensor, or a control board that may need replacing, those repairs go beyond a simple realignment.
Call (888) 290-7421Frequently asked
Why does my garage door open but not close?
Nine times out of ten it's the safety sensors. The opener will happily lift the door, but it won't let it close if the photo-eye beam at the bottom is broken or misaligned, because it assumes something (or someone) is in the way. Clear the path, clean the lenses, and realign the eyes until both lights are solid.
What do the sensor lights mean?
Each photo eye has an LED. Generally, a steady solid light on both sensors means they're aligned and working. A blinking light usually means they're out of alignment or the beam is blocked. A completely dark light often points to a wiring or power problem rather than alignment.
Can I just bypass or disconnect the safety sensors?
We strongly recommend against it. Those sensors are a federally required safety feature that stops the door from crushing a child, pet, or car. Disabling them is dangerous and may violate code. The right fix is to realign or repair them, not remove them, and it's usually a quick job.
How do I know if it's the sensor or the opener?
If the door reverses only when closing and you see a blinking sensor light, it's the sensors. If both sensor lights are solid and the door still won't close, the problem is more likely the opener's logic board, the close-force setting, or the wiring, which is a good time to call a technician.
Rather leave it to a pro?
Licensed local techs, same-day service, upfront pricing, and a 1-year warranty.