Garage Door Sensor Blinking Red? 5 Easy Steps to Fix it!

Usually, when you see the garage door sensor blinking red, there is a problem.

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Garage door sensors play a crucial role in your garage door system and are required by federal law in most states to ensure the safety and security of your home and family. These sensors use an invisible infrared light beam between two units on either side of the garage door.

This beam acts as an effective safeguard, preventing the door from continuing to close or open when interrupted. This ensures that no accidents or damages can occur.

If you see your garage door sensor blinking red, it may indicate some issues. This is a common problem that affects different brands like Chamberlain, Liftmaster, Genie, and others.

In this article, we will explore the causes behind the blinking red light and provide five easy steps to fix it, so you can get your garage door back to functioning properly.

How Do Garage Door Safety Sensors Work

Garage door sensors are like the Batman and Robin of garage safety. They work together to ensure your garage door doesn’t come down on your car, precious belongings, or, even worse, on you!

The garage door sensor system consists of two sensors, one on each side of the door tracks, that communicate with each other using infrared technology. When the door is closed, the sensors emit infrared light across the opening. If something breaks the beam, the sensors detect it and signal the garage door opener to stop it from closing.

For instance, If you’re closing the garage and forget your bike is underneath the door, As it begins to close, a sensor on one side of the door detects it. It sends an alarm for the opener to stop moving immediately – preventing accidents from happening!

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5 Common Reasons Why Your Garage Door Sensor Blinking Red

Now, let’s discuss some common garage door sensor issues you may encounter and how to fix them.

1. Misaligned Sensors

A Genie garage door sensor blinking red might mean it is misaligned.

If your garage door sensors are flashing red, chances are they’re misaligned. This means that the two sensors don’t have a direct line of sight to each other, or they may be at uneven heights. Aligning them properly will help you get back on track in no time!

Inspect if any material obstructs your sensor’s line of sight, like dirt or spiderwebs, to calibrate them properly. When that’s done, angle the sensors so they are precisely level with each other and at equal distances. With this simple step, you can guarantee a precision alignment of your sensors!

Think of your garage door sensors like a romantic couple trying to make eye contact. If one partner looks off to the side or is shorter than the other, they won’t be able to connect. So, ensure your sensors are aligned, and they’ll be able to “see” each other again, allowing your garage door to function properly.

2. Blocked Sensor Path

Stuff in your garage can block the garage door sensor light.

Have you ever tried to walk through a crowded room without bumping into anyone? Well, that’s the same for your garage door sensors. If something is blocking their path, they won’t be able to “see” each other and will start blinking red.

For example, imagine you have a stack of boxes in front of one of your sensors or your kid’s bike parked too close to the other sensor. This could cause your garage door to malfunction and refuse to close properly.

To fix this issue, try moving any obstructions out of the way of the sensors. If there’s something too heavy to move, try covering the sensor with cardboard or similar material until you can remove the blockage. Just remove the cover once you’re done to avoid any long-term problems.

3. Dirty Lens

Dirt and cobwebs will block the garage door sensor light.

A dirty sensor lens is like trying to see through a foggy windshield – it won’t work well. When the lens or receiver gets dirty, it can’t detect the signal correctly and causes the red blinking light.

To fix this, grab a clean, dry cloth (or a soft and lint-free microfiber cloth if you’re feeling fancy) and wipe down the lens and receiver to remove any dirt or grime blocking the sensor’s signal. You can also use a can of compressed air to blow away any debris that’s stuck in hard-to-reach areas.

Just like you can’t see clearly with a dirty pair of glasses, your garage door sensors can’t function properly with a dirty lens. So, giving them a good cleaning is essential now and then to keep them working at their best. And if your sensors are still blinking red after cleaning, it’s time to move on to the next possible fix.

4. Loose or Damaged Wires of the Sensors

When you notice there is no light on garage door sensor, most likely the there is a loose or cut wire.

Another possible garage door sensor issue is loose or damaged wires. If your garage door sensors’ wires become disconnected, they cannot communicate with other parts of the electrical equipment.

As a result, both red indicator lights on the sensor will start flashing – signifying an issue that needs immediate attention! To fix this issue, check the wires connected to each sensor to ensure they’re secure.

You can tighten any loose wires or reattach them to their proper connections if you find any loose wires. But it’s best to call a professional if you need help with this or feel like there’s a risk of damaging the property or injuring yourself.

5. Faulty Sensor

A faulty sensor can happen for various reasons, such as physical damage, misalignment, or interference from other electronic devices.

If you notice that your garage door sensors are blinking red, it could be a sign that one or both are faulty. In such cases, it is crucial to replace the sensors to ensure the safety of your garage door.

To reset or replace a faulty sensor, you can follow these steps:

  • Check for physical damage: Carefully evaluate the sensors for any signs of destruction or anything obstructing their path. If there is damage, you may need to replace them immediately.
  • Realignment: Make sure the sensors are correctly synced. If not, you can rectify this by changing their angle until they correlate.
  • Cleaning: Clean the sensors to remove any dust or debris blocking their path.
  • Interference: Check if any electronic devices near the sensors could be causing interference. If so, move them away to a different location.
  • Replace sensors: If none of the above steps work, it’s time to replace them.

For instance, a faulty sensor could be caused by a mischievous squirrel that chewed the wiring or a power outage that damaged the sensor’s circuitry. Or your sensors have seen better days, and it’s time to upgrade. Either way, take action before your garage door starts malfunctioning!

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How Do you tell if a garage door sensor is bad?

If you want to check the indicator lights of your garage door sensor, most brands, such as Liftmaster and Chamberlain, have them on either side or bottom of the sensor. A tiny LED light will give off a spectrum of colors that can tell you your sensor’s state at any moment.

Typically, a green light indicates the sensor is working correctly, while a red light indicates a problem. If you notice the indicator light blinking red, the sensors are misaligned, which can prevent the door from closing correctly. In this case, you should adjust the sensors until the red light stops blinking and turns green.

It’s important to always consult your manufacturer’s manual for specific instructions on troubleshooting any garage door sensor issues.

How to Troubleshoot Garage door light blinking and not closing

To troubleshoot a garage door that is blinking and not closing, the first step you should take is to locate the sensors at the bottom of each garage door track near the ground.

After identifying the sensor’s location, you can measure the height from the ground to ensure proper alignment. 

Garage door sensors can become misaligned for various reasons, with bumping or knocking of the door being the most common. To measure the sensors, here are the steps you can take:

  • Measure the garage door height from the ground and ensure that the garage door is level.
  • Use a ruler or measuring tape to measure the height of each garage door sensor – they should be 6 inches from the ground.
  • If you find that one garage door sensor is higher than the other, gently adjust it until it is level with the other.

Alternatively, if your garage door sensors are aligned correctly but your garage door still isn’t working, you can perform a self-test to determine if there is an issue. The following steps will demonstrate how to perform a garage door sensor self-test:

  1. Locate the photo-eye sensors. One is installed on the left side, and the other is on the right side.
  2. Check the LED light on the side of each sensor. A steady green light means the sensors are functioning correctly.
  3. If one or both sensors have a flashing red or no light, it may indicate a misalignment issue.
  4. Check the lens of each sensor for dirt, dust, or debris. You can use a soft cloth to clean any build-up that you find.
  5. Measure the height of each sensor unit. The sensors should be at equal heights and facing each other.
  6. Use a level to determine if the sensors are aligned. If they are not, they may have been installed improperly, or the mountings may have been damaged.
  7. If you find any sensor issues, call a garage door repair professional to diagnose and fix the problem.

Following these simple steps, you can double-check your garage door sensors for misalignment, fix the issue yourself, or call a professional for assistance.

Final Words

As explained, there are several potential causes for garage door sensors blinking red. Fortunately, most garage door sensor issues are relatively straightforward to fix.

Check for objects blocking the sensors, wipe down the lens and receiver, examine the wires connected to each sensor, and realign or replace faulty sensors as needed.

But if you need help diagnosing or fixing the problem, call a garage door repair specialist for help. Never ignore the garage door sensor blinking red, as it could indicate something more serious.

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Daniel Walter

Daniel Walter is a garage door expert with 15+ years hands-on experience and a degree in mechanical engineering. He's on a mission to empower homeowners with all the knowledge they need to tackle any garage-related issue with ease. When he's not sharing his expertise, you can find him scaling mountains and basking in the beauty of the great outdoors.

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