Garage Door Sensors Blinking Red (Hint: Cleaning is Key!)

The safety sensors located on your garage door are entrusted with the critical task of keeping your family safe, especially your children and pets. 

However, knowing this didn’t lessen my frustration when I’d finally made it home after a long day, only to find myself staring at an open garage door that refused to close. If I had known more about the sensors and what the indicator lights meant, it would’ve saved me a ton of hassle. 

If the light on your garage door sensor is blinking red, it generally means that it has detected something in its path or that the two sensors are not aligned properly. If this is not the case, you must ensure the lenses are clean, check for physical damage/signs of moisture, and inspect the wiring for damage. 

cold weather can damage your garage door sensors due to the fact that metal contracts when it gets cold. 

Sensor-related issues can require help from a professional. However, with the information we’ll go over below, you’ll likely pinpoint and resolve the problem on your own. 

Both garage door sensors being green does indicate that they are working correctly. However, some models feature different indicators. Some brands will feature various combinations that will also indicate the proper functioning of the sensors. 

With most brands, this indicates that your sensors are working correctly as long as the red light is not flashing. If the red light is flashing, it means that your sensors are misaligned. 

How Garage Door Sensors Work 

Garage doors are required by federal law to be equipped with safety sensors that prevent the door from closing when something is detected in the path of the door. The sensors will not allow the door to close if someone or something is detected near it, which saves you and your family from injury or damage to expensive belonging like your car. 

If you need to solve a problem with your garage door sensors, understanding the details of how they function will help you better detect and solve the issue. 

Most modern garage door sensors utilize infrared technology to ensure nothing is in the door’s path before it opens or closes. They are placed near the ground, directly across from each other on opposite sides of the door. 

When you close the door, the sensors send infrared beams to one another and cannot be obstructed for the door to close. If the beam becomes blocked, it will reverse the action, and the door will open back up fully. 

The sensors are powered by electricity. The receptacle is generally located in your ceiling, and wires run from it to your sensors. 

How do You Test a Garage Door Sensor?

If you’re unsure whether the sensors on your garage door are working correctly, you can perform a simple test to ensure it is. 

To properly test your garage door sensors:

  1. Place a box or another object that is taller than your sensor lenses between the two sensors. 
  2. Use the button on your remote or garage to close the door. 
  3. If the door closes even though the object is blocking the sensors, they are not working. 
  4. If the door does not close, proceed to lay an object that is shorter than the sensor under the door. 
  5. Activate the opener to close the door. 
  6. If the door reverses and goes back up, it is working correctly. If not, the sensors are not working correctly. 

If your sensors failed either or both of the tests, the steps below will walk you through determining the cause for your sensors failing and how to fix it. 

Why is My Garage Door Sensor Blinking Red – Signs to Look For

1. Light Indicator 

The meaning of the indicator lights on your sensor could vary slightly based on the brand of your equipment. However, most models follow a similar code. 

If the indicator light on your sensor is green, everything is functioning as it should. However, if the light blinks red, it means that something is not working correctly. 

If the indicator light is blinking red, it’s likely because the sensor has detected something in the path of the door that will not allow it to close. If this is not the case, it indicates other issues that you’ll need to resolve to stop it. 

2. Dirty Lenses 

Check the lenses on your sensor to ensure that they are clean. If the sensor is dirty, it’s likely the cause of the blinking red light. 

Things like dirt, dust, and cobwebs may seem insignificant, but they can easily cause the sensor to perform incorrectly, given their sensitivity level. If something is on the lens, there is a good chance the sensor thinks that something is in the path of the door. 

If this is the case, you can fix the problem by cleaning the sensors with a clean cloth. It’s best to clean your sensor regularly to keep them from failing, especially if your garage tends to stay dusty. 

3. Damaged Wires 

The light could also mean that you have an issue with the wiring that runs to the sensors. The wiring is one of the most crucial factors in the sensors operating correctly. 

Locate the wiring that goes to each sensor and check thoroughly for signs of normal wear and tear or other damage to the wires. You will need to rule out any worn wires, signs of water, or other damage. Other damages may include signs of chewing by pets, bugs, mice, etc. 

If you discover the wires are damaged, you will need to contact a professional to repair them.

4. Obstruction of the Sensor’s Path

If an object is in the sensor’s path, it will not allow the door to close, and the red light will flash. This is the sensor’s safety feature in action. 

If you’re experiencing this issue but don’t see anything in the sensor’s path, sweep the area well, then clean the lenses. 

5. Sensor Alignment Issues 

Incorrectly aligned sensors are one of the most common reasons you’ll see a red blinking light on your sensors. In order for the sensors to function properly, they must have a clear view of one another.

If one, or both, of the sensors, become loose, their lenses may not be placed where they can detect one another. This will trigger the red light and prevent your door from closing.

You may need to tighten the screws used to secure them. If so, be sure to shut off the door’s power supply before you begin working to ensure your safety. 

6. Moisture  

If the humidity levels are high or the temperature surrounding the sensors is fluctuating, it can create condensation on the lenses of the sensors, which will prevent them from seeing one another. 

You should wipe the moisture away immediately to prevent water damage. If the sensor already has water damage, it will need to be replaced. 

7. Damaged Sensors 

If you haven’t determined the cause for your blinking red light with the information above, you probably have a damaged sensor. Check your sensors for any signs of physical damage. 

These sensors generally only last up to five years. So, if your sensors are nearing this age, it is more likely that you’ll need to replace them. 

How to Reset Garage Door Sensor 

  1. Locate the button labeled Learn or Home on the main part of your system that is located on the ceiling. 
  2. Press and hold this button for approximately 10 seconds, or until you see the indicator light or the light bulb flash. 
  3. Next, your remote will need to be reprogrammed. Consult your user manual for brand-specific steps to do so. 
  4. Test the sensors. 

If this does not reset your sensors, try cutting off the power supply to your system for thirty seconds. You can do this by unplugging it or cutting off the breaker. 

After 30 seconds, restore the power source and test the sensors again. 

What are the Steps for Replacing Garage Door Sensors?

  1. For your safety, kill any power running to the system using the correct breaker before you begin
  2. Take the sensor down and remove it from its casing. 
  3. Cut the wires approximately 1 inch away from the sensor.
  4. Locate the wires on the new sensor, and use a crimp wire nut to connect them to the control wires, matching them according to color. 
  5. Place the sensor in the bracket and secure it with a nut. 
  6. Repeat steps 1-5 for the sensor on the other side of the door. 
  7. Restore the power.
  8. Line up the sensors.
  9. Test the sensors. 

Common Garage Door Problems

The Garage Door Won’t Open or Close

The cause behind a door not opening or closing can easily be narrowed down based on the common activity of the door. 

If your door works at irregular intervals, meaning that it works at times and doesn’t work at others, it will generally be related to an issue with your remote or the wiring. 

If your door moves unnaturally when it opens or closes, it’s generally related to a hardware issue. The most common reason for this is the rollers falling off track. 

If the door makes no movement and you hear no sounds indicating that it’s attempting to move, the motor or opener wires have likely gone bad. 

The Garage Door Shakes When Opening or Closing. 

A shaky garage door is generally related to one of the following things: 

  • Bad Tracks: Check the tracks for any signs of damage. You’ll also want to look for a buildup of things like dirt or rust.  
  • Damaged Rollers: Check the rollers for damage and ensure they turn correctly without locking up. 
  • Loose Belt: Check the belt that aids the movement of the door for loosening and other wear and tear. 

All of these are likely causes of your door shaking when it opens or closes. 

If all of these parts check out, add a bit of lubrication to them. Even in good condition, these parts will not move smoothly if they are dry. 

Noisy Door Operation

If your door is noisy, it could be related to:

  • Loose belt: If the belt that moves the door up and down is loose, it will allow the door to shake, creating a significant amount of noise. 
  • Loose Bolts: Loose bolts on the door will generate noise as they are rattled by the door moving. 
  • Faulty Springs: Bad springs will create creaking or screeching sounds when the door moves. 
  • Opener Bracket: A worn opener bracket interferes with the distribution of pressure placed on the door as it moves, making the movement noisier. 
  • Friction: If the trolley and rollers do not have a lubricated surface to travel on, it can cause a substantial amount of noise. 

Broken Garage Door Cords and Wires 

Garage doors feature opener cords and wires that allow the automatic functioning of the door. The wires provide electricity, and the cords provide stability by supporting the door’s weight.

If the cords break, your door will fall. So, replacing them as soon as you notice wear is best. However, if the wires fail, the circuit will be dead, and you’ll need the help of an electrician. 

Why Does My Garage Door Stop When Closing?

You should check the set-limit switch if nothing is blocking the safety sensors. 

The set-limit switch tells the motor where to stop, so if the door isn’t closing completely, you may need to adjust this setting. It is usually located near the motor, but the location may vary by model. 

My Garage Door Won’t Close ( 4 Simple ways to Fix)

1. Check the Sensors

If your garage door won’t close, it’s likely an issue with the safety sensors located close to the floor. The simplest way of checking them is to check for a green indicator light. If this light is on, it lets you know that your sensors are functioning correctly. 

If the light is red, it means that something is preventing it from working correctly. In most cases, it’s due to the sensors being out of line or dirty. However, it could also indicate a wiring issue that is causing the sensor to produce the wrong signals. 

If none of these are the case, your sensors may need to be reset or replaced. 

2. Check your Remote

If you are trying to close the door with a remote, there could be an issue with your remote rather than the door. If the problem is with your remote, you’ll need to:

  • Change the batteries in your remote. The most common reason the remote may not allow your door to close is due to low or dead batteries. Some remotes need to be reset after installing new batteries. 
  • Make sure you are close enough to the door. Your remote will only work within a certain distance. If you’re out of the range that the remote needs to be within to work, you’ll need to move closer. 
  • Check your antenna for damage. If you have a visible antenna, check it for signs of any physical damage. 
  • Reprogram the Remote. There are certain events, such as a power surge, that can interfere with the memory of your door. You will need to reprogram the remote if something like this has occurred. 

3. Check the Trolley

The trolley is a mechanical device that runs back and forth to move the arm that enables your garage door to open automatically. If you can move your door by hand, the trolley may be disabled. 

However, if the trolley is moving and the door still will not close, you’ll need to contact a professional for repairs. 

4. Check the Rollers and Tracks

The first thing you should look for is ensuring that the rollers are sitting correctly in the tracks. If the rollers have fallen off track, they will not be able to move your door. 

You’ll also want to check for objects that may have fallen into the track or buildup on the track that could prevent the rollers from traveling through them. If you notice any type of buildup, you may just need to thoroughly clean the tracks. 

Last, make sure there is no damage to either of them. If there is, you’ll need to have a professional fix the damaged part. 

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It’s crucial that safety sensors on your garage door work properly at all times to ensure the safety of everyone in your home. The importance rises significantly higher if you have children or pets that will be near the door. 

The user manual for your door opener will be able to provide more specific details pertaining to the meaning of your indicator lights and how to fix them. 

Most sensor issues can easily be fixed on your own. However, you should seek the help of a professional for more complex matters such as those that involve wiring.