One of the most common statements that I hear when fielding calls usually starts with: “My door won’t close. It starts to close, then it stops and goes right back up.” Nine out of ten times this means that something is wrong with the safety eye sensors.
The eye sensors are located at the bottom of the garage, inside small plastic box-shaped casings on both the left and right sides of the door. One sensor is the sender, and it shoots an invisible signal over to the other side, which is usually referred to as the receiver. This invisible signal creates a barrier going from one side of the garage to the other. When the door is open, this barrier is activated, and if anything such kids, pets or trashcans breaks that barrier it alerts the opener that it should not close. This prevents damage to both the door and whatever is obstructing the signal. Most of the time this is a good thing. However, sometimes the eye sensors get jostled or loosened and the barrier is continuously broken, even though there is nothing in the way. The safety sensor is now a problem rather than a benefit.
When the sensors are misaligned or non operational, the owner tries to close the garage to no avail. It will begin to close but the sensors will tell the opener to re-open before it reaches the bottom. Since the door is opening fine, the owner usually cannot understand what is going on. Even a garage savvy customer can get frustrated because they clean off any cobwebs or dust from the eye sensors and it still isn’t communicating properly. If a quick dusting does not solve the problem, the next step is to look at what the eye sensors are telling you. Each one has a colored LED light on the side of the plastic casing that is telling the owner how it is operating. One is green and the other could be green as well, red or an amber color. The color does not really matter as much as the strength of the light. The lights should be fully lit at all times without any kind of fluttering or blinking. A blinking light indicates a broken signal that can usually be remedied by cleaning or moving the eye sensor to be parallel with the other one so that it can send and receive the signal properly. This is the best case scenario as it can usually be fixed by the owner and a professional is not needed. However, sometimes there is no light present. The absence of light altogether means that the safety sensors are not operating at all. This is usually caused by a pinched or cut wire and would need to be re-wired or replaced by a garage door professional.