Garage door sensors must be aligned to ensure your garage door opens and closes properly.
How to fix garage door sensor alignment.
If your garage door sensors are outside of this range remove them entirely from the garage door frame and install leveled inside the safe zone.
This is a brief demonstration on how to adjust the safety sensors on your garage door.
In other words something is probably blocking the beam.
Since the sensors are often placed 6 above the ground all sorts of items could get in the way.
Lower is easy to stand above with a foot on either side.
But if the light on the receiving sensor is blinking you may have problems with garage door sensor alignment.
Proper height for a garage door sensor is 4 to 6 inches 10 2 to 15 2 cm.