How to Adjust Garage Door Sensors

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Plus, troubleshooting tips to fix sensors that aren’t working

Co-authored by Ryaan Tuttle and Devin McSween

Last Updated: April 20, 2025 Fact Checked

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Aligning the Sensors

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Signs the Sensors Aren’t Aligned

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Troubleshooting

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Video

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Expert Interview

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Q&A

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Tips

Garage door sensors protect your family, possessions, and pets by not allowing the heavy garage door to close if there’s anything in its path. They do this by using electric eye sensors that cross the doorway. If one sensor doesn't receive the infrared beam emitted by the other sensor, the door won't close. However, if the sensors get out of alignment, the garage door won't open or close at all. Fortunately, it's not difficult to realign the sensors and put things back into working order. With the help of home improvement specialist Ryaan Tuttle, we’ll explain how to align your garage door sensors and troubleshoot the issue if the sensors still aren’t working properly.

How to Realign Garage Door Sensors

Turn off the power to your garage.
Loosen the screws on the sensor mounting brackets.
Connect a string between the 2 sensors.
Adjust the sensors as needed to ensure the string is level.
Tighten the screws on the sensor mounting brackets.
Turn the power back on and check that the door opens and closes.
Ensure the sensors are connected by checking the LED lights.

Section 1 of 3:

Aligning Garage Door Sensors

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1
Turn off the power to your garage sensors using your circuit breaker. Go to your home's breaker box and find the switch for your garage’s power. Simply turn the switch to the “Off” position to cut the power to the garage door sensors.^{[1]
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- You won't actually be working with the electrical wiring when you align the sensors, but it's always best to be safe when working with electrically powered objects.
- Tuttle says it doesn't hurt to check the wiring first (with the power turned off) to ensure that your garage door sensors are receiving power.^{[2]
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  Ryaan Tuttle
  Home Improvement Specialist
  
  Expert Interview}
Don't take the screws all the way out. Just loosen them enough so you can slide the mounting brackets up and down, but they won’t move or fall off by themselves.^{[3]
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Pull the sensors downward so they are as low as possible. Just make sure you don’t slide them so far down that you unscrew the mounting brackets.^{[4]
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Knot a string around 1 sensor and run it across the garage doorway to the opposite sensor. Then, tie the other end of the string to the second sensor. Tuttle advises that you position the knots so the string runs across the center of the sensors, where the lenses are.^{[5]
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Ryaan Tuttle
Home Improvement Specialist

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To ensure the string is straight and the sensors are aligned, Tuttle suggests placing a level against the bottom of the string. If the string isn’t straight, adjust the sensor brackets by sliding them upward until the level is balanced.^{[6]
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Ryaan Tuttle
Home Improvement Specialist

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6
Tighten the screws to secure the sensors in their new position. If the string is completely straight, simply tighten the screws on the sensor brackets. As you tighten them, just make sure neither the string nor sensors get out of alignment again.^{[7]
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- Gently tap and shake the sensors to ensure they’re secure and won’t move out of alignment.
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Remove the string and turn the power to your garage back on. Untie the string from the sensors and flip the breaker switch to your garage’s power back to the “On” position. Once the power is back on, test the garage door opener to make sure the sensors are aligned and working.
- If your garage door isn’t opening or closing, it’s possible that something else is causing it not to work properly. Don’t worry—we’ll provide some troubleshooting tips in the section below.
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Ensure the sensors are making a connection. When you realign the sensors, Tuttle says you want to make sure the “lasers meet up and the eyes from the sensors are making a connection.”^{[8]
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Expert Source

Ryaan Tuttle
Home Improvement Specialist

Expert Interview} Most sensors have LED lights on them that indicate if the sensors are connected. Depending on the brand you have, both lights might be a steady green or one might be green and the other yellow or red.^{[9]
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- Check the user manual that came with your garage door sensors to determine what the different LED colors mean.

Section 2 of 3:

How to Tell If Your Garage Sensors Aren’t Aligned

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A clear sign that your garage door sensors aren’t aligned is if the door doesn’t open or close when you tell it to. Because the sensors aren’t able to communicate, the door might stay open when you want it closed, or stay closed when you want it to open.^{[10]
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The LED lights on the sensors are flashing red or yellow. Most garage door sensors have LED indicator lights that signal when the sensors are working properly or when there might be an issue. In general, a flashing light that’s yellow or red means the sensors aren’t aligned.^{[11]
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- Note: The LED lights mean different things depending on the brand you have, like LiftMaster and Chamberlain. So, consult your user’s manual to find out what colored lights indicate the sensors are misaligned.
If the sensors aren’t aligned, it’s also possible that the garage door might close even when something is blocking the sensors. Since the sensors can’t communicate properly, they won’t know if something is in the way and might close the garage door anyway.

Section 3 of 3:

Troubleshooting Faulty Garage Door Sensors

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Double-check that there isn’t anything blocking the path of the sensors, no matter how small. Make sure that everything in your garage is at least a few feet away from both sensors, like your car, tools, storage boxes, or outdoor equipment.^{[12]
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Dirt, grime, and dust can cover the sensor lenses, preventing the sensors from properly sending and receiving the infrared beam. Just lightly dampen a soft, microfiber cloth and gently wipe the lens on each sensor until they are both clean.^{[13]
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Shade the sensors from the sun. Direct sunlight can sometimes affect the sensors and prevent them from communicating. If possible, unscrew the brackets and turn the sensors on their sides so the sun doesn’t hit the lenses. Or, attach a toilet paper tube or sun shield onto the sensors so they shade the lenses from the sun.^{[14]
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- You can quickly check if the sun is the issue by shading the sensor with your hand or another object and trying to open or close the garage door.
4
Check if the sensor wires are damaged or disconnected. It’s possible that damaged or loosely connected wires are preventing your garage door sensors from working. Turn off the power to your garage and inspect the wires running from the sensors to the door opener, taking note of any that show signs of damage or are loose.^{[15]
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- If you notice any issues with the wires, contact a garage door repair specialist to fix them.
If your garage door sensors still aren’t working, the sensors themselves might be damaged or simply too old to function. Call a garage door repair specialist to come check out the issue and replace the sensors.

Community Q&A

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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.

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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.

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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.

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Tips

If you have a laser level, Tuttle says you can use that instead of a string to align your garage door.^{[16]
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Expert Source

Ryaan Tuttle
Home Improvement Specialist

Expert Interview} In this case, set up the level aligned with one sensor, then adjust the opposite sensor until the beam of your laser level is hitting the sensor.

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The proper height for a garage door sensor is 4 to 6 inches (10.2 to 15.2 cm) above the ground. Anything higher than that can miss low-lying objects, including pets. Anything lower is easy to stand above with a foot on either side.

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