Frequently Asked Questions About Garage Door Sensors

9 August 2021
 Categories: , Blog


A garage is as good as its door. Without a fully functioning door, your garage is a security threat. One of the typical garage door repair services involves garage door sensors. Here are some of the frequently asked questions regarding garage door sensors.

How Does a Garage Door Sensor Work?

To understand how a garage door sensor functions, you need to be familiar with two essential elements of the sensors: photo-eye and line of sight. A photo-eye refers to the infrared sensors that are on each side of the garage door. The remote control of your garage door sends a signal to the photo-eye when you want to open the door. The photo-eye prevents the garage door from shutting down on something or someone.

The photo-eyes on both sides of the garage door send infra-red beams to each other when you open the door and nothing is blocking it. If this infra-red beam is not interrupted by anything, the door will close. However, if an object, animal, or person comes in the way of the beam, the door will reopen. The uninterrupted beam that allows the door to close is known as the line of sight.

How Do You Test Whether Your Garage Door Sensors Are Faulty?

One of the best ways to diagnose whether your garage door sensors are working is by performing a cardboard test. During this test, you only need to take some cardboard boxes and fix them under the garage door. Because the sensors are around 6 inches from the ground, use boxes that are above this height.

When you try to close the door, a fully functional door will remain open because the boxes interrupt the line of sight. However, if the door continues closing until it breaks the boxes, the sensors are out of alignment. 

What Are Other Signs the Garage Door Sensors Have a Problem?

Some signs can help you note if there is a problem with your garage door sensor. First, blinking LED light indicators will tell you whether the garage door sensors are misaligned when you try to shut the door. When you see red lights blinking, the sensors are out of alignment.

Dirty lenses are another sign that you have a problem. In many cases, the sensor lenses accumulate dirt that blocks their view. Lastly, damaged wires can cause your garage door sensors to malfunction. The wires that connect the sensors may be worn out because of regular use.

Other factors that affect these wires include pest infestations and weather conditions. In many cases, your garage door repair expert will advise you to replace these wires.

If you notice a problem like this, contact a local garage door repair service.