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Symptoms of a Bad Garage Doors Sensor and How to Test it? [Video&FAQ]

Author: Apogeeweb
Date: 21 May 2022
how to bypass garage door sensors


Ⅰ Introduction

Ⅱ How do Garage Door Sensors Work?

Ⅲ 4 Kinds of Garage Door Sensors

3.1 Safety Sensors

3.2 Pressure Sensors

3.3 Monitoring Sensors

3.4 CO2 Sensors

Ⅳ Are Garage Door Sensors Universal?

Ⅴ Symptoms of a Garage Doors Sensor and How to Test it?

5.1 The Garage Door Won’t Close

5.2 The Photo-Eye Sensor Lights

5.3 Sensor Lenses

5.4 Sensor Power Supply

5.5 Sensor Wire Damage

Ⅵ How Do You Repair Garage Door Opener Sensors?

Ⅶ Garage Doors Sensor FAQ


Ⅰ Introduction

Safety sensors are intended to prevent accidents caused by automatic garage doors, which have resulted in major vehicle damage, as well as injuries and deaths among humans and animals. They are an element of the garage door opener system. In reality, since 1993, these safety sensors have been mandated by law. Mechanical sensors are the most common type of sensor, in which a moving garage door reverses due to physical contact with an object, however, photoelectric sensors have become more common.


Garage Door Sensors



Video: How To Realign Garage Door Sensors in 5 Minutes or Less!


Ⅱ How do Garage Door Sensors Work?

An infrared beam is used by photoelectric sensors. Two sensors are aligned and set about 6 inches above the floor on either side of the entrance. As a result, an undetectable trip wire is generated. A car tire, a person's leg, a tiny child, or a pet can all be spotted at that level. When something blocks the infrared beam's passage, the door will automatically stop halfway open and reverse course.


Unless the emergency lever is pulled, the door will revert to its original position. It can only be forced to close after that.


Sensors are sold in pairs, one for each garage side. They both have one eye that is facing the other. To signal the door to close, each eye must be able to "see" the other. Your garage door will stop shutting and reverse its motion to open again if they are unable to convey that signal. If your door won't close, the sensors may have failed.


 4 Kinds of Garage Door Sensors

You press a button, and your garage door opens as if by magic. Isn't it ridiculously simple? On the surface, this appears to be a straightforward process, but it involves a complicated system of sensors, infrared illumination, and other technical components to get your door to do what you want when you want it.


Safety sensors, pressure sensors, monitoring sensors, and CO2 sensors are the four fundamental types of garage door sensors. Each has its function and purpose, but they're all created and constructed for flawless performance and unparalleled safety. Here's a closer look at each sensor type:


3.1 Safety Sensors

Garage door safety sensors prevent the garage door from shutting on objects such as cars, pets, rubbish, or people. These are usually fixed on the rails on either side of the garage door. The sensors communicate with one another via infrared beams, and if the beams are interrupted, the door will stop and reverse direction. These sensors detect anything that is still or enters the course of the beams unexpectedly.


3.2 Pressure Sensors

When a garage door comes into contact with another object, pressure sensors installed along the bottom edge of the door will stop and reverse the door's downward closing motion. These sensors are meant to detect even little levels of pressure, preventing the door from shutting on someone or something!


3.3 Monitoring Sensors

Monitoring sensors are designed for homes with many garage doors and inform owners when one of them is open. These work with receivers that are placed in the home or via a smartphone application. In many circumstances, these sensors can remotely close the door or be programmed to close after a given amount of time. Because an open garage door can be a source of risk for burglars, these sensors are frequently included with home security systems.


3.4 CO2 Sensors

The accumulation of carbon dioxide in a garage can be fatal! CO2 sensors use cutting-edge technology to constantly monitor CO2 levels in the garage and, if necessary, automatically open the garage door. These sensors are less frequent than other types of sensors, but they can help keep you and your family safe.


 Are Garage Door Sensors Universal?

Garage door sensors all work in the same way and have the same function. Sensors are available in a variety of brands. Some types are advertised as universal, which indicates that they will work with garage door openers from companies like LiftMaster, Chamberlain, Craftsman, and others. This means that no matter what garage door opener the sensors are attached to, they will give the same level of safety once installed.


Ⅴ Symptoms of a Garage Doors Sensor and How to Test it?

The everyday use of the garage is disrupted when the garage door begins to malfunction. You're probably wondering how to identify whether the garage door sensor is broken and how to fix the problem. Let’s see.


Symptoms of a Garage Doors Sensor


5.1 The Garage Door Won’t Close

The garage door malfunction is the first clue that anything is amiss with your garage sensor. Something is incorrect if the door opens without difficulty yet closes with difficulty. Another possibility is that the door closes but instantly reopens.


In both cases, something interferes with the sensors, and they react as if there is an obstacle between them. That is why the door reopens to prevent an accident that can damage an object or injure the person under it.


The garage door may not open or close properly for a variety of reasons. First and foremost, check to see if the sensors are malfunctioning. Testing them using a few cardboard boxes is one of the simplest methods.


To test if the garage door sensors are working properly, place a few cardboard boxes under the open garage door. Because the sensors are around 6 inches (15 cm) above the ground, you should select higher boxes.


You can now attempt to close the garage door. The boxes should disrupt the beam of light between them if the sensors are in line and working properly, and the door should remain open. Another alternative is for the door to begin shutting before touching the boxes and then opening.


If the garage door sensors are malfunctioning, the door will not stop until it reaches and damages the boxes. It's possible that the door closes completely, as if there are no boxes within, and the boxes are destroyed. It can also partially close and reopen after hitting the boxes. The sensor security function has failed in both circumstances.


Switch to manual operation if the door destroys the boxes as it closes. Because it is impossible to forecast whether or not the door will slam without recording small impediments, children, or pets, you should close the garage door and not use it until the problem is resolved. You will avoid any potential mishaps this way.


5.2 The Photo-Eye Sensor Lights

The photo-eyes sensors on the track of the door are about 6 inches (15 cm) above the ground. The green LED light is on one sensor and the red LED light on the other. A green light on the sensor shows that it is sending a light beam, while a red light indicates that it is receiving one.


One of these two lights will go out or blink if the sensors are malfunctioning. That typically implies the light signal between them has been interrupted, or the sensors are not on the same level. In both circumstances, they are unable to carry out their duties properly.


Photo-Eye Sensor Lights


If the red light flashes but the green light continues to work normally, the sensors are out of alignment. It would be beneficial if you adjusted them by moving them slightly till both lights are switched on.


However, you should investigate whether the sensors are malfunctioning exclusively during certain times of the day. Sensors are sometimes affected by the sun. If the sun's rays strike one of the sensors at an angle, they will interfere with the light beam and create a malfunction.


A simple option is to place cardboard in front of the sensors to shield them from the sun's beams. Always carefully place the cardboard so that it does not interfere with the signal between the sensors. Otherwise, you'll just be replacing one issue with another.


5.3 Sensor Lenses

Dust and filth will gather on the sensor lenses daily if you live on a busy street and your garage door is frequently opened. Because they're pea-sized, they get filthy quickly and stop transmitting the signal to close the door.


Sensor Lenses


When you wipe and carefully clean the sensor lens, you can rapidly establish a blocked signal. Remove the cobweb from around the garage door using a broom, and then wipe away the dust with a soft cloth.


To make sure you've solved the problem, repeat the test using the cardboard boxes. Check sure the sensors are receiving an uninterrupted signal so that the door opens and closes normally.


Furthermore, extreme humidity can cause sensor malfunction. You should expect little drops of water to penetrate the sensor if you reside in a rainy location. Wipe the sensors with a dry cloth outside first. Then unscrew the metal holders and inspect them on the inside to see if they are moist.


Lawn sprinklers are another source of moisture in the sensor's lens. Water might pose an issue if the sprinklers are too close to the garage. Move them out of the way so that no water reaches your garage door.


5.4 Sensor Power Supply

The green light on the sensor indicates that there are no issues and that the power supply is working properly. If both lights on the sensors are off, the sensors are powerless and unable to respond.


Check to see if the cable is disconnected, as this will prevent the garage door from closing. Due to a voltage decrease or a power outage, the fuse may blow. The sensors will become active after the power supply has been restored.


5.5 Sensor Wire Damage

Wire damage is one of the most serious issues with garage door sensors. A sensor that flashes orange instead of the usual red light may signal this problem, depending on the garage door model.


Examine all wires coming from the sensor to the rear of the opener's terminals. If the cables are tangled, untangle them and inspect them for any damaged or twisted wires.


A staple or a nail sliced through the wire insulation can occasionally be seen. For the garage door to work effectively, all cables must be intact and properly connected to the garage door opener. Keep in mind that the white wires should be connected to the white terminal, while the black and white wires should be connected to the gray terminal.


If you see that wires are in the wrong place or are broken, you should contact an electrician. You can repair the sensor wiring yourself if you have the necessary skills.


Sensor Wire Damage


Electric shock can occur if wires are connected incorrectly. Furthermore, the garage door opener may experience serious failures, resulting in additional costs.


 How Do You Repair Garage Door Opener Sensors?

After you've determined that your garage door sensor isn't working for one of the reasons listed above, you can try a few basic tweaks to see if the problem can be solved. To fix your garage door opener sensors, use the following two methods:


Dirty lenses: A garage door that won't close is most likely because of this. The problem could be caused by unclean lenses, which is the most obvious cure. These lenses are made of the same glass as camera lenses. Door sensors' picture eyes are small and readily clogged. Clean with a gentle cloth and a streak-free mild cleaner. Wipe dirt or residue from the eye's surface using a soft cloth. Don't get your eye overly wet because it will attract extra dirt.


Out of alignment: Another cause of garage door sensor failure is misaligned photo eyes. The photo-eyes must all be facing the same way and at the same angle. Each sensor features an LED light on the outside. The sensor is out of alignment if one of these lights is blinking. Use a screwdriver to tighten the screws on the bracket holding up the blinking LED light until it is in alignment with the other one. You can also do this by bending the bracket back into its original position. Once you realign the sensor lights, the blinking will stop.


Now it's time to put your skills to the test. Place another cardboard box in front of one of the camera's eyes. The remote control should be pressed. Your goal is complete if the door starts to close but then reopens because the beam between the corrected photo eyes is now blocked. If, on the other hand, the door continues to close, crushing the new cardboard box, you may have a more significant issue.


Check that the lenses have been thoroughly cleaned, that the picture eyes are aligned, and that no LED light is blinking. One last time, put the cardboard to the test. If the door won't open and closes on the cardboard box, it's time to call in a technician to inspect the entire system.


 Garage Doors Sensor FAQ

How To Disable a Garage Door Safety Sensor?

Until you get your garage door safety sensor working, you may want to disable it until professional help arrives to ensure nothing gets damaged. You can gently twist one, so the sensors do not line up, which will temporarily disable the sensor. You may not want to try anything more in-depth until you have professional help, as you don’t want to damage the system permanently.


Should both sensors on garage door be green?

Each sensor will usually have a light. One will have a green light, used to show that the units are powered up, and the other will have a red light to show that there's no obstruction between the sensors and that they're 'seeing' each other.


Will garage door work without sensors?

Since most photo eye sensors are placed at that two-inch height, most people know you can simply step high above the infrared light to bypass the system. The garage door will continue to close if your steps avoid the photo eye sensor. Disconnecting the garage door opener from the garage door will bypass the sensors.


What does it mean when one garage door sensor is green and one is yellow?

A steady green light indicates that both sensor units are powered up and are always supposed to be lit. The green light is visible when nothing is obstructing the sensors and properly aligned. The yellow light indicates that the transmitter sensor is sending a ray.


Are there batteries in garage door sensors?

The battery needed is a 3V disc –shape called “CR2032”. They can be found at many retailers like Walmart or Home Depot, and even in most grocery stores, usually by the hearing aid batteries.

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