garage door sensors

How To Align Garage Door Sensors

At Presto Garage & Gutter, one of the most common garage door repair calls that we get are related to the garage door safety sensors. In this post, we’ll cover a few of the basics including what garage door sensors are, how they function, and how to align them. We’ll also look at different solutions available that can help fix garage door sensor issues from reoccurring.

What Are Garage Door Safety Sensors?

In the early 1990s, new laws were put in place to help keep homeowners safe from being injured by closing garage doors. This increase in safety requirements was called the UL 325 standard. Essentially, the law stated that a garage door must have a safety reversing device. To meet this new standard, manufacturers began producing garage door openers with safety sensors.

Openers are now also built with settings that allow the motor to sense if the garage door has touched an object while closing, and are meant to reverse the door when this happens. The UL 325 standard helps maintain a consistent level of safety for manufacturers to follow as they produce new garage doors. Even with these in place, there are several issues that can prevent your garage door safety sensor from working properly.

How Garage Door Safety Eyes Work

At Presto, we sell high-quality garage door openers from reputable manufacturers like LiftMaster® and Linear motors. While our team is experienced in a wide range of openers, the advice discussed in this post is based on how these specific brands of openers generally function.

LiftMaster and Linear openers come with two sensing units. One of the units is a sending unit, and the other is a receiving unit. The sensors’ “safety eyes” are pointed straight at one another, so that a laser beam emitted from the sender is received by the sister unit. In the event that an object is in the way of the garage door closing, the beam between the two units becomes broken and the garage door opener will reverse. A light may flash as a warning of the impediment and the motor won’t close the door until the issue is resolved.

Common Reasons For Garage Door Sensors Not Working

After several decades helping Carolinians fix garage door issues, it’s true that sometimes your garage door safety sensors have reached the end of their useful life and will need to be replaced. But it is far more common that a simple issue caused by everyday wear and tear is keeping your sensors from working properly.

The top reasons why your garage door won’t close are:
  • The two sensors have been knocked out of line alignment with one another.
  • A foreign object is obstructing the beam between the units.
  • The beams are covered in cobwebs or other debris that’s preventing a solid beam from being transmitted and received.
  • Bright sunlight hitting the sensors is interfering with the signal’s integrity.

How to Align a Garage Door Sensor

If you have a safety beam that’s out of line, the good news is the fix is usually fairly easy to accomplish in just a few minutes. You may need a screwdriver or pliers to help loosen the connecting wingnut of the mounting bracket holding each sensor. Work to point the sensors straight at one another until they are aligned properly. Visualizing as close as possible will usually do the trick but most units now also have LED lights on the safety sensors that let you know when they are aligned correctly.

If the quick realignment method doesn’t work, you’ll need to move on to a slightly more involved process. Here’s the solution in a few easy steps:

  1. Turn off power to the sensors.
  2. Using a screwdriver or pliers, loosen the screw holding the unit into the mounting bracket.
  3. Adjust each unit to 6” off the ground. If placed too high, the sensors will fail to pick up something low enough to go underneath.
  4. Hand-tighten the mounting bracket screws just enough to hold each sensor in place.
  5. Run a string from one sensor to the other.
  6. Use a level at the bottom of the string and adjust as necessary to get level.
  7. Tighten the mounting screws all the way to keep them in place but be careful not to jostle out of position.
  8. Turn back on the power and test the unit.
While realigning the units, it’s also a good idea to clean them well. Using a soft towel, brush any debris off the unit being careful to wipe the sensor lense. Make sure any objects are well away from the sensors and the garage door’s path. This will keep the door from being damaged, and won’t cause issues with reversing when you try to close.

Fixing Garage Door Sensor Sunlight Issues

In some cases, customers have bright sunlight shining down on their garage doors causing their garage safety sensors to fail. When your door is open, this bright light can be stronger than the beam emitted from your garage door sensors. When this happens, it can confuse the opener by breaking the beam and causing the unit to reverse or refuse to close. LiftMaster makes a great safety sensor sun shield kit that our technicians can install to help eliminate this issue.

Overriding a Garage Door Opener System

If you are having issues with sunlight or something else that you can’t figure out, it’s easy to override the safety mechanism to get your door to close. On door opener models installed by Presto, it’s usually as simple as holding down the close button until the door seals to the floor. You can also utilize the emergency release cord which disconnects the door from the opener carriage so that it can be closed manually.

Please note, these remedies don’t fix the underlying problem, but they do allow you to close the door and secure your belongings until your scheduled service appointment takes place. Whenever you need to override your garage door safety system, always make sure there are no pets, children, or any other objects nearby that might be in the path of the door closing.

Installing Garage Door Sensor Guards

garage door sensor guards If you have issues with your sensors frequently getting knocked out of line, you can usually solve this issue for good with garage door sensor guards. These guards wrap around the units, so that they can’t be bumped out of line and afford an additional layer of protection from everyday wear and tear.

Our technicians can have these units installed quickly and professionally both for on-track or wood framing-mounted units. We always recommend having sensor guards installed with any new garage door opener installation. They’re relatively inexpensive and help prolong the useful life of your garage door sensor unit.

Is Your Garage Sensor Receiving Power?

Before you schedule a time to have a Presto technician install new garage sensors, make a final check of the electricity being supplied to your units. If you don’t see any lights illuminated on your sensor, this can mean that the sensor is not receiving power.

With the power supply turned off, check the wires leading to the sensor for any loose connections. Also, check your breaker box for a tripped breaker. You’d be surprised at how many electrical issues are solved with tightening a loose wire. However, if you’re still having issues related to the power to your garage door sensors, it’s recommended to call on a licensed electrician.

How to Tell if Your Garage Door Sensor Needs Replacement

If you’ve checked the alignment, cleaned the unit and the space around them, and have checked for electrical issues but your sensors are still not working, it may be time to replace your garage door sensors.

Presto technicians will diagnose your garage door sensor issues during the service call and then outline a plan of action going forward. We’ll never proceed on a repair or install any parts before you give our team permission to do so.

Schedule a Service Call to Fix Your Garage Door Sensor

At Presto, our technicians have the experience and tools necessary to get your garage door back online quickly. For garage door repair and sensor issues, we’ll diagnose the root causes and walk you through all your options so you can make the best decision for your situation.


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  • Hi, I'm Tisha Broome. I'm one of the owners here at Presto. I'm an expert in helping clients choose the right garage door, garage floor and gutter system. I can also help you with all of your repair and maintenance needs. You can text me with any questions. I typically respond in less then 15 minutes during normal business hours. I'm available to speak by phone, email or by video call if you'd like me to see the visual details of your project.

  • Terry Caldwell
  • Hi, I'm Terry Caldwell. I've been a member of the Presto Team since 2015. I've been working with clients to choose their perfect product solution since 2018. Before that, I was our lead garage door installer and then our lead repair technician. I can help you find solutions to even the most difficult problems. Feel free to text me your questions. I typically respond in less than 15 minutes during business hours. I'm available to speak by phone, email or by video call if you'd like me to see the visual details of your project.