Overhead garage doors all have safety sensors installed. One on each side of the garage entrance. These are there to stop the door from continuing to close if there is an obstacle in the path of the descending door. They significantly reduce the risk of injury and damage to items, such as your car. It is important, then, that these sensors stay in proper working order. 

One way that you can test the sensors is to place a cardboard box under the open garage door. Choose a box tall enough that it should be recognized by the sensor (usually about six inches off of the floor). Then, try to close the garage door. The box should break the beam of light between the sensors and cause the door to either remain open or start to close, but then re-open well before it hits the box. If the door only re-opens after touching the box – or closes entirely and destroys the box! – then the sensors are not working properly. In that case, attempt to fix them as soon as possible, and consider not using the door until they are fixed to avoid possible accidents.

Beautiful facade with Garage Doors

Here are a few tips about what to look out for in case your sensors are not working and how you might fix them.

1. Even with no obstruction, the garage door will not close.

One sign that the sensors may not be working properly is that the door has difficulty closing. Or perhaps it does close, but then immediately reopens. It is possible that the sensors think that there is something between them and are trying to do their job in preventing injury – even though the way is clear. 

2. The sensors are not properly aligned with one another.

Check the lights on your sensors. The sensors on the door’s track are usually about six inches above the ground. One sensor has a green light – which is sending a beam of light. The other sensor has a red light – which means it is receiving the light. If either of these lights goes out or is blinking, something is interrupting the signal. Perhaps they are not lined up on the saae level. If, for example, the green light is working, but the red light blinks, then it is likely that the sensors are not aligned, so the red light is not consistently receiving the green light’s beam. You might try moving them slightly to realign them. 

3. The sensor lenses are blocked by dirt or debris.

If your garage door often stays open or opens and closes frequently, then it is possible that dust and dirt has built up on the lenses of the sensors. The sensors are quite small, so it may not take a lot of accumulation to interfere with the signal.  Excessive humidity (or even sprinkler water) can also cause water drops to work into the sensors and cause a problem.

To check if this is causing the problem, simply carefully wipe clean the sensor lenses and the immediately surrounding area. For moisture, wipe the sensors with a dry cloth, and then unscrew the metal holders to check if they are wet on the inside. 

4. The power supply to the sensors has been interrupted.

If both the red and green lights are off, then there is likely an issue with the power supply. If only the red light is off, it might be that it is simply unaligned with the green light. Both off – and especially the green light off – and you should check on the power.

5. There is damage to the wires leading to and from the sensors.

If nothing else seems to solve the problem, you might carefully inspect all of the wires leading to each sensor. (It is possible that if there is a problem in the wiring, one of the lights may flash orange.) All of the wires need to be properly connected and unbroken for the sensors to work well. If you see that a wire is broken or frayed or connected incorrectly, please contact a professional. Improperly attempting to fix wires can result in injury or more significant malfunctions. 

Garage door sensors prevent the door from closing while an object or person is underneath. It is vitally important that they are working correctly. As soon as you notice there is a problem with the way the door closes or a problem with the lights, check the sensors. If you cannot resolve the issue on your own, please contact us, so that we can help. We want to make sure that your door is as safe as possible for you and your family.