Why Is My Garage Door Sensor Not Working?

Nothing is more frustrating when you’re late than a garage door that won’t open or close correctly. Don’t leave your garage door system’s functionality up to chance. Check out these seven common causes for garage door sensors not working so that you can fix the problem for good.

1. Obstruction Blocking Sensor

Automatic garage doors work by using two sensors to determine if there is an obstacle in the way of closing the garage door. This mechanism is required in garage doors, as it prevents the doors from closing if they detect an obstruction. However, if your garage doors keep stopping and going back up when you’re trying to close them, there could be an obstruction sneakily preventing the sensors from doing their jobs properly. 

Check your garage door perimeters for signs of small obstructions that could be blocking the sensors from communicating to resolve the issue.

2. Sensor Misalignment

Sometimes, sensors get out of alignment from frequent movement in your garage or accidentally bumping them. When this happens, your garage door sensors may stop operating. You can identify misaligned garage door sensors by looking at the LED lights on the two sensors. The light should be a constant green, so if it’s blinking red or the garage door sensor has no light, there could be a misalignment problem.

To fix this problem, first measure the height of the sensors to confirm that they’re misaligned and determine how much you need to adjust them. Then, gently move the sensors until they’re at the same height. The LED lights should return to solid green if done correctly.

3. Power Supply Malfunctioning 

Power supply issues can also cause your garage door sensors to stop working. Check your breaker box to see if the switch has been tripped to rule out a circuit breaker problem, and make sure your garage door opener is plugged in. 

You can fix a flipped circuit breaker by unplugging the opener, flipping the switch back to the “ON” setting, and then plugging the opener back into the outlet.

4. Faulty Wiring

From incorrectly installed sensors to rodents chewing on the wires to mere old age, faulty wiring can be another reason for garage sensors not working. If it’s a wiring issue, you may feel confused by your garage door system’s inconsistent refusal to open or shut, but quickly getting to the bottom of a wiring issue is essential—especially if there’s a water issue at play.

If you’ve just installed the garage door system, you may want to have a garage pro inspect the system to rule out improper wire placements. If it’s an electrical wiring issue, your pro may have local electricians they can recommend to help you rewire or repair the wires in your garage.

5. Dirty or Wet Sensor Lenses

Garage door sensors easily get dirty from dust, debris, water, and dirt over time. If you leave your garage door open or operate it frequently, inclement weather can quickly lead to dirty sensor lenses.

You can clean your garage door sensors with a microfiber cloth, but in some cases, you may need to be even more thorough by removing the hardware and giving the entire sensor a good wipe-down. Stay on top of dirty, moist sensors by scheduling a time once annually to clean them off as part of your garage door maintenance.  

6. Sunlight Interference

Garage door sensors that stop working at just one time each day may have sunlight interfering with their ability to send the light to signal that it’s time to operate.

The best way to fix this issue is to protect the sensors from sunlight by strategically placing cardboard in a way that casts a shadow where the sun hits the sensors. Ensure the cardboard doesn’t prevent the sensors from sending and receiving light from one another.

7. Natural Wear and Tear

Garage door sensors can last anywhere from five to 15 years, or around 10 years on average. If your sensors have approached the ends of their lifespans, then it could just be a matter of replacing the sensors with new ones. Garage doors are heavy and can be dangerous for your average DIYer, so know who to hire to repair garage doors to be safe about any replacement parts needed. 

We recommend working with a local garage door repair company to help you replace your garage door parts come time to replace or repair. The average garage door repair costs between $150 and $375 on average—a price well worth the peace of mind that comes with having a functional garage door system.