Photo Eyes | Sensors | ISB’s

What are Photo Eyes, Sensors, or ISB’s?

These are all terms used with a Garage Door Opener.  Every Residential Garage Door Opener should have a set of photo eyes, sensors or Infrared Safety Beams (ISB’s).  If you don’t your garage door opener was manufactured prior to 1993 when it was put into law. All residential garage door openers will have infrared safety beams on every new garage door opener installed. It does not matter who the manufacturer is. Periodically you may have heard the stories on the news about a person being killed by a garage door opener or children getting stuck underneath the garage door because it didn’t go back up.  These are all real stories that happen to everyday people like you and I.

Garage door photo eyes sensors ISBs

They are small rectangular or box shaped sensors located at the bottom of your garage door either located on your track or attached to the wall.  By law, they are required to be no higher than 6” from the ground to follow UL325 code.

What is the purpose of the photo eye’s, sensors or ISB’s?

One word, “Safety”.   The ISB’s are there to prevent the garage door from coming down on someone or something and damaging whatever may be in its path.

There are several different manufacturers of garage door openers. Listed below are a few of the manufacturers and the kind of photo eyes, senors or ISB’s they have with that particular name brand.

LiftMaster/ Chamberlain/ Sears Craftsman

The old version of photo eyes was green on both sides.  The newer version has green on one side and yellow/amber on the other side.  If the ISB’s are out of alignment the light on the motor will flash 10 times.


The lights on Genie/Legacy ISB are green and red.  If the ISB’s are out of alignment, the red light will be flashing.


The lights on a Linear ISB’s on one side it has one green light and on the opposite side it has two lights one green and one red.


If the ISB’s on a Marantec are out of alignment the opener will/flash and beep until a new cycle has been complete


 The ISB’s are a yellow box with red lights that flashe when the sensors are out of alignment.

Sometimes the lights are flickering and all you have to do is adjust the ISB slightly until you see a solid light.

Five tips to check if the garage door is not closing

  1. Make sure no grass, leaves, spider webs or debris is lying on the ground, bottom panel or on the ISB’s.
  2. If your ISB’s are attached to the wall, make sure they are tight to the wall
  3. If your ISB’s are attached to the track, make sure the track is tight to the wall. The vibration can move them out of alignment.
  4. Don’t put anything in the alignment of the beam.
  5. Never spray your garage out with water, you may hit the ISB’s and short them out.

If all else fails, try cleaning the lens off with a paper towel or soft cloth as a speck of dirt or water spot can also make the door go back up. The lenses are just like glasses that get dirty, they need to be wiped off especially after it rains as dirt will attach to the lens.

If your door still isn’t going down….Call a A1 Affordable Garage Door Services 972-877-5774. Schedule an on-time appointment with one of our garage door specialists today! We service Plano, Allen, McKinney and the surrounding areas or if you want to replace your own photo eyes, sensors or ISB’s we carry them in our Plano showroom. Our showroom is located here.

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