How Do Garage Door Sensors Work? Know All About It

Garage door sensors are used in conjunction with a garage door opener. The sensor is installed on the door, and the other end of the sensor is attached to the garage door opener.

The garage door opener stops or reverses when it senses the infrared beam is broken by an object moving in front of it. A sensor can also be used to detect when the door is closed.

Automic garage door openers can be safety-enhanced depending on the homeowner’s or business owner’s needs. Sensors on the openers stop the door from closing or opening if there is an object in front of the sensor. Automic openers use a photo eye to detect objects. There are different brands of garage door sensors available in your nearest store.

In this article, I will give you a detailed analysis of how garage door sensors work, how to identify problems, and when to repair them.

How Do Garage Door Sensors Work

Garage Door Sensors Working System

A garage is equipped with two photoelectric sensors, which use an infrared beam. one for each side. The doors will not shut if one eye is covered. The sensors are designed to detect an obstruction in the way of the closing door. The photo eye system detects objects that are moving towards it. It is usually used with an automatic garage door opener.

The safety sensors are connected to the circuit board, which is driven by an electrical current that activates light bulbs and infrared beams when it is activated. When there is no obstruction in front of the sensor, then it will give off a green light that tells you that it is safe to close the garage door.

If there is an obstruction, however, then a red light will come on and inform you not to close the door until the obstruction has been removed.

The sensors are usually placed in front of the door, but they can also be installed on the sides. The sensors can be installed at a lower height or higher than the door itself, depending on your preference.

How to Test Your Garage Door Sensor Works Properly

Finding out whether your garage door sensor is working is quite simple. The issue is frequently simple to resolve once you figure out that the sensors are the problem. The following tips will help you know that your garage door sensor is working properly.

  • Test to ensure that the photo eye is working properly by standing in front of the sensor. If it is working correctly, the photo eye will open and close the door.
  • Check to see if the light is blinking, which indicates that the sensor is detecting something in its range. If the light is not blinking, then the photo eye could be defective and should be replaced.
  • Observe if the sensor’s alignment is correct.
  • Check for any obstacles in front of the photo eye to be sure that it can detect objects properly.
  • Check if there is an obstruction in the light beam, which may be causing the sensor not to detect objects properly.
  • Ensure that your garage door is properly aligned. If your garage door is off-track, then it will not close completely, and the photo eye will not detect any objects within its range. Loose wing nuts may cause misalignment, loose screws on the springs, an unbalanced garage door, and damaged or broken springs may also be the cause.
  • Check the condition of the weather stripping around the door. If the weather stripping is damaged or missing, then water can get in and cause wood rot or rust.

How to Tell if Garage Door Sensor Is Damaged

How to Tell if Garage Door Sensor Is Damaged

Below are some of the ways you can tell that a door sensor is damaged.

Cardboard Box Test

Place the cardboard in line with the detectors, and attempt to shut your garage door. If the door shuts after sensing the cardboard, you can be sure that it is operating properly. You must troubleshoot if it closes.

Test the Sensors

To test sensors, you must place your hand between the sensors and attempt to close the door. If it will not shut, check for any obstructions or any issues with the wiring.

You can also use a screwdriver to test the sensors. Place it in line with each sensor and try to close the door. If it does not shut, then you know that something is wrong with it.

If you have already replaced your sensors, but you still face issues when operating your garage door, then you may have some other problems, like a faulty circuit board or a misaligned door.

Assess for Witness

Assess the door’s operation. If it operates smoothly, then you can be sure that the sensors are working properly. But if you face issues while operating your garage door, then you may have to replace the sensors.

Inspect the Wire Damage

A damaged wire can also cause a garage door sensor to malfunction. The sensor wire connections are subject to tear and wear from regular use and are therefore prone to be damaged. Pests, wind, and rain all can do so. If you see signs of tampering, it’s time to replace the sensors.

Common Issues With Garage Door Sensors

Find out the common issues with garage door sensors and their remedies:

1. Light Indicators

Garage Door Light Indicators

When a sensor is triggered, an indicator will light up and stay on for about three seconds before it turns off. This helps you to identify which sensor has been triggered. However, if the indicator remains on for more than three seconds, then there is a problem with the sensor.

If the light does not turn off after it has been triggered, then the sensor will not turn on the opener. This is a sign that there is a problem with the sensor or its power supply. You will need to check it out before you can continue using your garage door opener.

2. Dirty Lenses

The lenses on a garage door sensor can become dirty. The dirt acts as an obstruction and prevents the light from reaching the sensor. To resolve this issue, you should clean the lenses using a soft cloth with warm water and mild soap or a lens cleaning solution.

If the lens is cracked or broken, then you will need to replace it.

3. Damaged Wires

The wires connecting the sensor to the garage door opener can become damaged. This may cause a short circuit, which will result in the sensor not functioning properly. You can use a multimeter to test for a short circuit by following these steps:

  • Set your multimeter to “ohm” (this is usually indicated on the front of your device) and set it to 300 ohms.
  • Locate the wires connecting the sensor to the garage door opener. This can usually be found on the wall of your garage or inside a box attached to the wall. You can also check your wiring diagram for this information.
  • Place one probe of your multimeter on each wire and press “test.” If you get a reading, then there is a short circuit in that particular wire. If you do not get a reading, then there is no short circuit in that wire. This issue may require a garage door specialist’s help to resolve, so it is recommended that you contact an electrician if this is the case.

4. Sensor Misalignment

Sensor misalignment can also cause the sensor not to function properly. The sensor may be misaligned in several ways.

  • The sensor maybe too high or too low
  • The sensor may be too far to the left or the right
  • The sensor is not facing the direction of the door
  • The sensor is tilted or canted

To solve the issue with misalignment, you will need to adjust the sensor in one of these ways:

Make sure the sensor is aligned with the door. You can do this by making sure that the sensor is centered on the door and that it is facing the direction of the door. If you are unable to align it yourself, then contact a garage door professional to help.

If the sensor is tilted or canted, then you will need to adjust the sensor so that it is original position. To do this, simply remove the sensor from its mounting bracket and straighten it up. You may need to bend the sensor a little bit, but be careful not to break it.

How to Take Care of Garage Door Sensors

Taking care of your garage door sensors can help them to last longer and work better. One of the ways of taking care of your garage door sensors is to make sure that you do not get them wet.

This can happen if it rains a lot or if you wash your car in the garage. Getting the door sensors wet can cause them to rust, which can make them stop working properly.

Another thing you should do is to keep your garage door sensors clean. If there is a lot of dirt and grime on the sensors, then it can make them less sensitive. This means that you will need to open the door more for it to work. You can clean the sensors with a damp cloth and mild detergent.

Having a limit switch in your garage door is very important. It can help you to make sure that the door does not go past its limits and hit something. If you have a broken limit switch, then you should call for garage professional assistance.

A professional specialist without much trouble can replace a limit switch, but for the average homeowner, it may be a little difficult.

It’s important to lubricate garage door systems’ moving parts, which include springs, tracks, rollers, hinges, and, in some cases, chains. Ensure that these parts are working correctly. Prior to using your garage door, wipe away any dirt and lubricate all the moving parts with a small amount of lubricant.

Keep everything running smoothly by tightening any loose wing nuts, bolts, or screws on your garage door.

Regularly check the wiring of your garage door. If you have a lot of rust on the wiring, then it may be time to call a professional to have it replaced. Wiring that is not in good condition can cause your door not to work correctly, and it can also be a fire hazard.

Cleaning the garage door sensors is an easy way to keep your garage door operating smoothly. The photoelectric garage door sensors should be carefully cleaned so as not to knock them out of alignment, which is six inches off the floor.

Frequently Asked Questions (FAQs)

Q: Can a Garage Door Work Without Sensors?

Yes, it can. You can use a manual garage door opener instead of the sensors. But if your garage door is made of metal and you want to use the remote control to open it, then you will have to install photoelectric sensors that are extremely sensitive to light.

Q: Do Garage Door Sensors Use Lasers?

Garage door sensors function with photo eye technology. Infrared sensors situated two to six inches off the ground on either side of the garage door open upon pressing the remote control. The sensors work in the same way as a camera, which can detect objects in its field of vision.

Q: Are There Batteries in Garage Door Sensors?

Yea, they do. A garage door sensor uses a 3-volt disc-shaped battery and operates wirelessly. You can find the coin cell battery at a store.

Q: Can Sunlight Interfere With Garage Door Sensors?

When garage door sensors are exposed to intense direct sunlight, the garage door might not close because the sensors cannot communicate with one another. The sensors might be unable to signal one another if the light of the sun is brighter than the infrared light. This issue can be resolved by installing the sensors in a shaded area.

Q: How Do You Trick Garage Door Sensors?

You can trick garage door sensors in the following ways.
Going manual: You can easily trick garage door sensors by opening the garage door manually. This is a great alternative if the sensor is not working.

Adjusting the sensors: You can adjust the sensors by moving them closer to the ground. This will help you from triggering the sensor when you are driving or walking on it.

Trouble-shooting: You can troubleshoot and check the sensors for issues. You might need to replace them if there are issues like broken sensors or loose connections.

Final Thoughts

Garage door sensors safeguard your family’s safety. To keep them secure, knowing how they function is a superb starting point. Some devices make your life easier by using infrared beams, photoelectric eyes, electrical currents, and invisible tripwires. Those devices are ‘fancy’ terms for a helpful technology that makes your life more convenient.

Everything leads to balance. Your safety sensors work best when everything is aligned for success, just like you! If you want to learn more about sensor functionality, please contact your garage system professionals.

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Ezekiel Mutitu

Ezekiel Mutitu is a man of many talents. He has an unquenchable thirst for knowledge, which has led him to do thousands of DIY projects. He loves learning about anything and everything - especially electronics and electrical items. Ezekiel knows that by being passionate about writing, he can help people from all walks of life understand complex topics and processes.

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