The Most Common Garage Door Issues – The Photocells | Overhead Door Company of Tampa Bay™

The Most Common Garage Door Issues – The Photocells


Issues with your garage door can be infuriating, to say the least. Most people are in a hurry to leave when it is time to open the garage door. No one seems to notice how important a functional door is until something goes wrong.

When it comes to problems with garage doors, many would assume that the main issue is with the door itself. The most common problem is actually due to a system designed to keep people safe – the auto-reverse system. 

Fortunately, problems with the system do not prevent you from getting in or out of your garage. It becomes an issue when it is time to leave for the day or go to bed at night and the door will not close.

If you find that your door will start down but then reverse back up with nothing in the way of it closing, you likely have an issue with the photocells that are in place to diagnose something below the door. The good news is most photocell problems can be quickly resolved with minimal effort.

What is the Photocell and What Does it Do?

Garage doors were once an inherent safety hazard around the home. The doors used to be even heavier than they are now. There were no protections in place for anyone or anything unfortunate enough to find themselves under a closing door.

In 1993, a regulation was put in place and adopted across North America requiring all garage door openers have an auto-reverse system in place. The systems would radically reduce the number of garage door related injuries.

The photocell (also called photo-eye) is an integral piece of a high-quality safety mechanism. Once cell is placed around half a foot off the floor on each side of the garage door along the door tracks. The photocell communicates with the motor that drives the door up and down.

A beam passes between the two photocells and if the beam is uninterrupted, the motor knows all is well. If the beam is broken by a person, animal, or object, the door immediately returns itself to the open position. 

There is a more rustic backup feature on garage doors in the event the photocells fail, malfunction, or become compromised (more on that next). The backup is a simple system that detects objects physically. If the door is closing and comes in contact with a person, animal, or object, the door will return itself to the open position.

What Could Be Wrong with the Photocells?

There may be times when your garage door refuses to close. It may start down the tracks but then quickly return to the open position. If this happens, the most likely cause is a misalignment of the photocells.

Photocells can be knocked out of alignment by contacting the door, something hitting the photocell itself, or temperature changes that cause settling. How can you tell if the photocells are out of alignment?

The first clue is the door refusing to close. Sometimes, a clicking noise will come from the photocells. Select garage door openers will feature a blinking light on the motor or on a control panel when the photocells are out of line.

How Do I Fix the Problem?

Fortunately, since photocell misalignment is one of the common garage door problems homeowners experience, it is one of the easiest issues to deal with. The major goal is to realign the beam so that it passes directly between the photocells.

The first step is to determine which photocell has moved. It is often obvious which one is the culprit. Simply replacing it to its original position could fix the problem. The clicking noise should cease or the light should stop blinking. The most obvious way to check is by attempting to close the door.

There are other issues that cause the photocells to misalign. Check to be sure that they have been secured appropriately to the wall. If the lenses become dirty, it can also cause the same symptoms as misalignment.

If you attempt these fixes and the problem persists, you may have a more complicated issue. It could still be a problem with the photocells but there may be a wiring issue or something else preventing communication between the photocells and the motor.

Once you get past the potential fixes listed here and determine there is a more serious issue, you should call in a professional. A garage door company like ours can help further diagnose the problem and recommend the best solution. 

Safety is Paramount

It is beneficial to check the auto-reversal system at regular intervals. To test the photocells, place an object in front of one of them as the door is closing. The door should return to the open position. 

Check the mechanical auto-reversal function by placing a 2×4 board or some similar size object on the ground under the door (it must be shorter than the photocell). If the door contacts the object and returns to open, you know the secondary safety system is working appropriately.

Safety regulations are only effective if they are followed. Checking to make sure your garage door safety systems work is important to protect you, your family, and your pets.


There are steps you can take to return your garage door to proper functioning when photocells are the issue. If you take the above steps and still experience issues, contact us to help.

Our experts excel at the diagnosis and resolution of every garage door problem there is. Do not compromise your safety by going it alone!

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