Garage door safety sensors (photo eyes) not working

If your garage door will not close, or starts down and goes back up, the safety sensors are a common reason. This guide covers the checks a homeowner can make safely, how sensor lights are used by some manufacturers, and when to stop. Sensor light signals vary by model, so check your model's manual.

Safety sensors, often called photo eyes or electric eyes, sit on either side of the door near the floor. One sends an invisible beam and the other receives it. If something breaks the beam while the door is closing, the opener is supposed to reverse the door.

CPSC describes the entrapment protection system as an electric eye, a door edge sensor or another device that provides equivalent protection. CPSC advises mounting an electric eye 4 to 6 inches above the floor. Chamberlain says its sensors are mounted no higher than 6 inches above the floor, usually on the tracks.

Because these sensors protect children and pets, a door that will not close with the sensors in place should be treated as a repair, not an annoyance. Do not remove or bypass the sensors to make the door work.

• The door will not close from the remote or wall control, but opens normally.
• The door starts down, then reverses before reaching the floor.
• The opener light flashes and the door does not move down. Genie says an operating problem can keep its opener from running closed, and Chamberlain says some of its openers flash the main lights 10 times for a safety sensor fault.
• A light on one or both sensors is off, dim or blinking. What that means depends on the make and model.

A door that closes but does not reverse on an object is a different problem. See auto-reverse explained and how to test your opener safety reverse. If the opener light blinks, why the opener light blinks covers what to look at first.

These checks do not touch the springs, cables or bottom brackets. Do them only if the door is closed or fully open, undamaged and on its track.

1. Look for an obstruction. Clear anything between or in front of the two sensors, such as a box, a tool, a bike wheel or a stray cord. Chamberlain lists clearing obstructions as the first step.
2. Check for direct sunlight. Chamberlain says direct sun on the receiving sensor can block the sending sensor's infrared beam. If the problem only happens at certain times of day, note when it happens.
3. Look at the sensor lights. Many sensors have an indicator light on each unit. Chamberlain says that on its units both lights should glow steady when the sensors are unobstructed and aligned. Genie uses a different system, with blinking lights on the opener itself. Check your model's manual for what the lights mean on your system.
4. Check that each sensor still points at the other. A sensor that has been bumped can point away. Chamberlain describes loosening the wing nut, aiming the lenses at each other until the sensor light glows steadily, then retightening the nut. Do this only on a sensor that is within easy reach, and only if your manual describes the same adjustment.
5. Test the door. Stand clear and close it with the remote or wall control. Keep the door in sight until it stops.
6. Look at the wire. Without pulling on anything, check for a wire that is cut, pinched or hanging off its clips.

Genie lists a similar short set of first checks for its models: look for an obstruction, check that the sensors are aligned, and look for a continuous obstruction in the beam path. Genie's list also covers a door that starts down then reverses, which it ties to obstructions or lens misalignment.

Sensor and opener light patterns are set by each manufacturer and are not universal. The examples below come from the manufacturers named. They do not apply to every opener, so check your model's manual.

Chamberlain also says that when both sensor lights are on or both are off while the sensors face each other, the cause is likely wiring or failed sensors. That is a repair, not an adjustment.

Stop and have a technician look at the door if any of the following is true:

• The sensor lights stay off, or both stay on, after you clear the beam and check alignment.
• A sensor wire is cut, pinched or loose, or the sensor is cracked or loose from its bracket.
• The door still will not close after the checks above.
• The door is crooked, off its track, or you suspect a broken spring or cable. Do not run it to see what happens. See when a garage door is unsafe to use.
• You are tempted to disconnect the sensors or hold the button to force the door shut.

Our technicians inspect the sensors, the wiring and the opener, and confirm the cause before replacing anything. See garage door safety sensor repair and garage door opener repair.

Sensors are meant to be tested as part of regular maintenance. Clopay lists testing the auto-reverse and photoelectric sensors in its maintenance steps and says a professional should inspect the door if it fails to reverse or the sensor does not respond. Chamberlain recommends testing the reversing system monthly. Add the sensors to your seasonal checks, using the annual maintenance checklist as a guide.

If your opener is old, or the sensors are not part of its design, see repair or replace an opener.

• Garage Door Safety Sensor Repair
• Garage Door Opener Repair

• Chamberlain: Troubleshoot the safety reversing sensors when one LED is off or flickering
• Chamberlain: Why the lights on my opener flash and my door will not close
• Genie: Garage door opener troubleshooting guide
• CPSC: Garage door opener safety
• Clopay: Maintenance and replacement guide