Garage Door Sensors & Overhead Door Opener Sensor Troubleshooting

Cleaning of the sensors and periodical testing of their response should be on your house maintenance schedule list.


Garage door sensors are also called photoelectric sensors, are designed to protect people and their belongings (not just cars) by constantly checking for an obstruction in the path of an automatically closing overhead door. As soon as something is detected, the garage door sensors send a signal to the garage door opener to reverse its movement and open the door.

A single pair of the garage door sensors includes a transmitter that emits an infrared beam and a receiver. In order to operate effectively, both of them must be properly aligned – the receiver eye must see the transmitter eye.

Each of the garage door sensors has a small “status” light that stays ON at all times on the transmitter side, and turns ON at the receiver side only if there’s a clear path between them. You might also have a receiver with a light that instead of turning OFF changes color to red or starts blinking when the infrared beam is broken.

Height of the garage door sensors

You should install each of the overhead door opener safety eyes (top of the lens) no higher than 6” from the garage floor surface. This is critical for small children or any individual lying down on the garage floor in the path of a closing garage door.

I would not recommend installing the photoelectric garage door sensors very close to the floor surface.

  • Placing the sensor within and inch or two from the floor might result in leafs or other small debris triggering the overhead door opener false responses.

Under no circumstances should you install the garage door sensors anywhere else. Sometimes I see them taped together on top of the garage door opener or secured to the roof/ wall framing, which creates a serious safety hazard – do not do it!

Overhead garage door sensors troubleshooting


  • When you push the garage door opener button, the door starts traveling down, but as soon as you release the button – it reverses automatically. The following are just the most common issues under the assumption that the safety eyes itself and the garage door opener are not mechanically damaged.

Things to investigate

  • Check for any obstruction in the infrared beam path, it might be a spider web, leaf, etc.

  • Check the garage door sensors lens and clean it if necessary (transmitter and receiver)
  • Check alignment of the sensors / make sure that both of the status lights are constantly ON. If they are not, try to slightly adjust the transmitter or receiver – if this works, secure them in place.
  • Wave your hand in the path of an infrared beam to see if one of the garage door sensors status lights turns OFF / changes color to RED / starts blinking

If there’s no status light on either of the garage door sensors, make sure that the wires at the garage door opener terminals and at the sensors (if not permanently attached) are secured / wiggle them slightly to see if none of them have separated / broken at the screw that is holding them.

  • It is also possible, that the wire between the overhead door opener and the garage door sensors got accidentally damaged / cut – check the entire length.

If none of the above helps to correct the garage door closing, you may need to call a professional to investigate the problem.

You can also check the overhead door opener post for more information about the garage safety issues.

I hope this will help you in troubleshooting and proper installation of the garage door sensors.

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