Garage door opener safety sensors are a critical part of your garage door opening system. They are also a very vulnerable part as well. Malfunctioning garage door sensors have, in the past, been one of our top service calls for garage doors and one of the most common causes of a garage door not closing.  So, we have put together the common causes of garage door sensor problems and how to fix them.


Closing, when diagnosing and fixing, during garage door sensor issues.

Garage door safety ropeWhile you are having issues and are trying to solve those issues with your garage door sensor, your door may not close. Obviously, this is a safety concern for you and your family. There are a couple of easy solutions to close your garage door while having a sensor problem. Simply pull the red safety rope to release the door from the garage door operator and close the door manually. If you have a wall console button, hold down the button to begin closing- then release the button just as the door sets down (requires a bit of timing).

Where to locate the garage door sensor.

Garage door sensorMost garage door openers have safety sensors installed on both sides, right and left, about 3-4 inches from the ground located on the lower piece of the vertical tracks of the garage door itself. You will find wires from the sensor going to the garage door opener motor head.


Common causes of garage door sensor problems.

One of the common causes of garage door sensor problems is obstruction. In many cases, the garage is where a lot of stuff is stored. Some of these storage items, such as a broom or shovel or even a box, can block the sensors’ view of each other. To fix it, check to make sure that there is nothing in the way of the invisible sensor beam. Look from left to right along a straight line in between the sensors and move anything that may be in the way. Dirt, grime, and cobwebs on the sensor lenses can also obstruct your garage door sensor. Check the sensor lenses and clean away dust and cobwebs as needed by using a paper towel or soft cloth.

Another cause of a garage door sensor issue is the sensor getting hit, whether by car, pet or moving things around. If they have been hit, they can be misaligned or even damaged. Make sure that the sensors are accurately pointed at each other by eye-balling the path and adjusting or redirecting if needed. Sensors may need a slight adjustment even if the LED lights are illuminated on both sides.

To Align the Sensors:

  • Loosen the wingnut on each sensor.
  • Adjust the sensor until the LEDs are glowing steady and tighten the wingnuts.
  • Use the remote control to close the garage door.
  • If the door closes, test the safety reversal after this adjustment, and you’re done.
  • If the door doesn’t close, check wiring connections.

Corroded or bad wire connections are another common cause of garage door sensor issues. Pets sometimes chew the wiring. Also, the humid/wet Houston air can rust or corrode connections. You will want to check the wires to make sure they are still connected and not damaged or chewed. When the receiving sensor (green LED) has power, the LED will glow steadily. If the LED is not glowing steady, this means there is an open or shorted wire.

Trouble-shooting a shorted or open wire

  • Replace the wire currently connected to the sending sensor.
  • If you have replaced the wiring and the sensor is still not glowing steady, replace the safety reversal sensors.
  • Use the remote control to close the garage door.
  • If the garage door closes, test the safety reversal after this adjustment, and you’re done.
  • If the door doesn’t close, try switching the position(s) of the sensors.


A lesser-known possible issue could be a total failure of the logic board of the sensor. Symptoms of this could be: If the garage door moves downward only an inch or so, OR the head unit blinks and makes a clicking noise, OR the lights on the sensors are off, blinking, or flickering.

Guide to Adjusting the garage door sensor.

We have also a step by step on how to adjust your garage door sensor, just click here:  It is common for the garage door sensor to have an issue here or there due to wear and tear of homeownership throughout the years.

To avoid bigger, more costly issues, Spectrum Overhead Door LLC in Houston, TX offers a garage door tune-up, which we can inspect your sensors lessen the chance of having sensor issues down the road.

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Garage Door MaintenanceCommon Causes of Garage Door Sensor Problems