Do you have an automatic door in your garage? Have you ever imagined how do garage door sensors work? Garage door sensors are created to avoid accidents that occur due to automatic garage doors. In 1926, CG Jonson invented the first automatic garage door.
In 1993, the federal government made it mandatory for door-making companies to have sensors in their doors because of safety purposes. As a garage door sensor is a vital part of an automatic garage door it is needed to know how it actually works. In this article, we have tried to give you proper information about it.
What is a garage door sensor and how does it work?
Garage door sensors are basically a safety feature in automatic garage doors. It prevents the door from closing if there is something under it. The garage door sensor works with two features.
- Photo-Eye: Garage door sensors use a photo-eye system. These sensors are basically inferred and they are placed on both sides of the garage door about two to six inches up from the ground. When you give a command to open the door with your remote control it sends a signal to the door to open. But the main feature of the photo-eye system is to avoid closing when there is something beneath the door.
- The line of sight: The photo-eye system on both sides of your garage door will send an inferred beam to each other when the door gets opened and there is nothing beneath it. The door will close automatically if there is nothing to interrupt the beam. But if there is something that is interrupting the beams the door will not close instead it will get re-opened.
How can you tell if your garage door sensors are working or not?
Garage door sensors not working? How to figure it out? Garage door sensors come with a default function that let you know if there is any problem. Wrong alignments, dirty sensors, or any damaged part can lead the sensor to malfunction.
A sensor can be thrown away from the alignment if there is something that bumps into it or the connection wire might get damaged by any impact. It might happen due to vibration from the garage door or direct sunlight. This might be the reason because of why the door isn’t working properly.
If the sensor is glitched, the door will stop suddenly and will reverse for no reason. It will get opened but not get closed. Or a light might get flashed on the sensor from an overhead component.

Steps to make sure your garage door sensors are working properly
Step 1: Calculate the Sensors’ Height
The first step is to measure the height of your garage door sensor. Now get some cardboard boxes that will cross the height of the garage door sensors.
Step 2: Place the box in the middle of the sensors
The next step is to keep the boxes in front of the door so that the boxes get hit by the inferred beam of light. Now try to close the door by pressing the close button of the remote control to see if the sensor can detect the boxes If the door does not close and gets reversed then the sensor works perfectly. But if the garage door closes then there is something wrong with the sensor.
Step 3: Check the LEDs on the Sensors
The next step is to check the sensor’s inferred light. Every unit of the sensor has default LED inferred light. Check if there is any kind of blinking in any of the LEDs. If so you need to realign the sensor.
This means there is no overlap between both sensor’s inferred beams and it needs to be adjusted. You can do it by tightening them with the screw holding the sensor. LED sensors will stop blinking after doing this.
Step 4: Make Another Test
When the testing is done removed the crushed cardboard boxes and replace them with the new ones. Perform step 2 again. If the door closes again then there is something wrong with the dirty lenses on the sensors.
Step 5: Lenses on the sensors should be cleaned
Clean the lenses on both sensors and perform another test. The most common problems of the lenses are dirt and spider web which cause interruption. This does not let the sensor work properly. Also, ensure that the sensor’s wires are not damaged. Repeat the test as before.

Frequently Asked Questions (FAQ)
1. How long do garage door sensors last?
Answer: Sensors that are properly maintained can endure a long time. They will wear down more quickly if you do not undertake routine maintenance on them, such as cleaning them and tightening screws.
You can identify if you have a bad sensor or merely need to modify its orientation now that you know how to check if your garage door sensors are aligned. If moving and cleaning your sensors doesn’t help. Quality Overhead Door will repair or replace them to keep your family and property safe. Schedule a service or contact us for more information to get the help you need.
2. Garage Door Sensors: Can They Be Repaired?
Answer: Yes, the garage door sensors can be repaired without consulting a technician. Dust, improperly placed sensors, and other factors are some of the most prevalent reasons for sensor failure. If you decide to fix the sensors on your garage door yourself, turn off the electricity to the sensors first. If the issue is related to wiring, contact a technician because you will not know how to properly solve this issue, which can be harmful.
Human error can cause sensors to fail in various instances. Some of these issues include dirt on the sensors that receive or send the light beam, improperly fitted sensors, and so on.
Final Words
Garage door sensors are a must when it comes to safety issues. In this article, we have tried to explain to you how do garage door safety sensors work. Not only that we have also tried to explain the steps that you might follow to ensure that your door sensors are working properly which will prevent accidents. If you are still having issues with your garage door sensors then it will be wise to call a professional for help.