If your garage door sensors are not working properly, they may be either dirty or out of alignment. To be sure they are clean, use isopropyl alcohol on a cotton swab and wipe the sensor glass. If they still are not functioning properly you can align them yourself. When you have properly functioning garage door sensors, this valuable safety system may save the life of a child or pet.
Turn off the electric breaker or disconnect from power supply to prevent electrical shock while working on the sensors.
The garage door sensors are located approximately 4 to 6 inches from the bottom of the garage door rail frame on each side. Loosen the screws on each sensor so that they require a small amount of force to move up or down.
Adjust each garage door sensor to no more than 6 inches off the ground. This is the maximum height for the sensors.
Tie the string to each sensor.
Bring the level up to the string so that the string is above and gently touching the level. If the string is not level, adjust the sensors to level the string. Check that each sensor is no more than 6 inches from the ground.
Tighten the screws on each sensor and check the string after tightening the sensors so that the string is still level.
Untie the string from each sensor.
Turn on the breaker or reconnect power supply.
Test by rolling a basketball between the beams to be sure that the garage door sensors are functioning properly.
If the garage door sensors do not work, clean the sensor glass with isopropyl alcohol on a cotton swab, there may be fingerprints on the sensor. If the sensors still do not work, they may need to be replaced.