How to Align Garage Door Sensors

Last Updated: July 2, 2020 Approved

Garage door sensors protect your family, possessions and pets by not allowing the heavy garage door to close if there is anything in the glide path. They do this by using an electric eye sensor that crosses the doorway. If the sensor doesn't receive the beam emitted by its opposite number, the door won't close. This seems like a clever device until the components come out of alignment -- meaning the door won't close at all. Fortunately, it's not difficult to realign the sensors and put things back into working order

Steps

1
Turn off the power to your sensors by tripping the fuse for your garage. You'll find this in your home's breaker box.^{[1]
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- You won't actually be working with the electrical wiring, but it's always best to be safe when working with electricity.
2
Loosen the screws that mount each of your garage door sensors. Don't take them all the way out. Just loosen them enough so that the mounting brackets can slide up and down, but won't do so unless you intentionally move them.^{[2]
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3
Slide each garage door sensor downward so it is as low as possible without unscrewing the mounting brackets.^{[3]
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4
Tie a string to one sensor so that, if pulled across the garage doorway, it will run across the center of the sensor.^{[4]
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5
Run the string across the garage doorway and tie to the opposite sensor. Position the knot so the string runs across the center of that sensor, too.^{[5]
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6
Lay a level so the bottom runs along the string. Check that the line of the string is level.
- If the line of the string isn't level, adjust 1 or both garage door sensors by sliding the mounting bracket upward. Continue until the sensors are once again level.
7
Tighten the screws to secure the garage door sensors in their new position.
8
Confirm that the string is level before finishing. The sensors may have come out of alignment when you tightened the screws.^{[6]
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9
Finish by removing the string and turning the power to your garage back on.

Community Q&A

Question

One sensor is green and the other yellow. Why is that?

Community Answer

The "orange/red" eye is putting out the infrared beam to the "green" receiving eye. If the green is not lit or blinking, it needs to be adjusted until it is a steady ON green or the door will not operate.
Question

I have a wall-mounted controller to open and close my garage door. When I push the close button on the controller, I have to hold it down until the garage door is completely closed. What can I adjust or fix to make the garage door close with just a push of the button?

Community Answer

It sounds like your sensors are out of alignment. You are bypassing the safety by holding the button down. Check to see if the light on each sensor is on and then realign from there.
Question

How high off of the ground should the garage door sensors be located?

Community Answer

They should be 6-9" off the floor, and make sure they're equal. There should be an LED indicator light on the top or back of each unit that lights up when the sensors are parallel and aligned. You may have to adjust the sensor brackets up and down or side to side to achieve this.
Question

Will the sensor stop the door from hitting the top of the car?

Community Answer

Yes, the laser sensor will detect the car and the door will stop moving.
Question

When I close my electric garage door it keeps opening again, and each time I hit the button to re-close it, it opens again until finally it stays closed. Most of the time this happens in the evening when it's hot. The sensor lights at the bottom on each side are green & the other is yellow/red. What can I do?

Community Answer

It may or may not be the heat. It could be the time of the season or angle of the sun shining on the sensor.
Question

Only one of the sensor lights is on. Do I need to replace the sensor with the light out?

Community Answer

Check the wiring from the non-working sensor to the opener. On my opener, the wire from the sensor splits in two at the opener and each wire connects to a different screw. Try reversing how the wires are connected to the screws.
Question

My garage door will not close when the sun shines in the doorway. I have to hold the button for it to close. Why does this happen?

Community Answer

This is because the sensors have a broader light spectrum than infrared, and the light that comes from the sun completely blocks the receiver from capturing the infrared light from the sender. A higher quality sensor might solve this problem.
Question

How do I adjust so that my garage door reverses when it hits a 2 x 4 block that is laid flat on the floor if my Genie garage door opener failed the safety reverse test?

Community Answer

The safety reverse test is based on how much effort the motor that moves the door needs to apply to open or close it. If it fails, it is because the garage door opener does not consider that the obstacle requires too much force to close. Making sure that the belt that moves the door has the proper tension might help to mitigate this issue.
Question

What would cause the sensors of a Genie garage door opener to glow red and green?

Community Answer

That indicates a normal function. The beam is detecting an object when the red led is blinking.