Automatic garage doors run on a complex interplay of different parts, and so it may not always be easy to identify where a problem lies in the event it comes up. Because the garage door is so heavy, any small malfunction can result in an accident that may critically injure or even kill someone. The following paragraphs highlight some safety features to check for to ensure proper function is maintained.
1. Photoelectric sensors
The photoelectric sensors are 'eyes' installed on either side of the garage door frame, a small distance from the ground. Their purpose is to detect any obstacle in the way of the garage door and stop the door from closing. Basically, each time the door is moving down, these sensors are supposed to 'see' each other. If they don't, it is usually because of an obstacle, and the door will be prevented from closing. Many injuries have happened because of malfunctioning sensors.
To test functionality, start with the door fully open. Close the door using your transmitter while standing just outside the door's path. As the door is closing, wave an object, such as a piece of wood, across the path of the sensor. Properly working sensors should immediately cause the door to stop and reverse to the fully open position.
These sensors should not be installed too high up—no more than 5 inches from the ground—because they should be able to detect obstacles which are very small. Also, they must be installed at the same height and door frame position for proper communication. These are easy to check for, and necessary adjustment is also easy.
2. Opening force
The door is raised and lowered by a force created and countered by the door springs. To check the force of the door, simply grasp the bottom of the door during the close cycle when it reaches the halfway point. This should cause the door to stop. If this doesn't happen, it means there is an excessive opening force, and you can reduce it by turning the force knob anticlockwise.
Older doors were designed to stop when they hit an obstacle, but this may be dangerous in cases of malfunction when a child or pet is involved. You can, however, also test for this function by placing a fairly thick piece of wood on the path of the garage door. The door should reverse completely upon touching the piece of wood. If this doesn't happen, the downward force needs to be adjusted.
After making an adjustment, ensure the opener runs both the open and close cycle before trying the test again. Keep adjusting until the door closes easily and stops easily. Be sure not to go below the minimum force required for door opening (you can check the manual for this).
Contact a garage door maintenance company for additional advice.