Garage doors have many parts that all work together including safety features.
Garage door reopens when closing.
If the door stops short of closing lengthen the close limit by turning the control knob in the direction indicated usually counterclockwise.
The symptom of this is a garage door that is in constant motion opening fully then immediately descending only to start the same cycle again.
Close the garage door with the opener and watch it closely as it closes.
Check the track and tension spring.
Most garage door openers have an open and close limit control.
In garage door operators made after 1993 there are required safety features that open the door during the close cycle when they detect something blocking the door.
There may also be loose wire connections inside the button housing itself.
Garage doors have sensors that keep them from closing on top of an object so you ll need to check to make sure there isn t something blocking the way.
As these wires short against the housing the electrical impulse causes the door opener to activate.
Even a very small item can set off a sensor so give the area a thorough comb over and make sure there s absolutely nothing out of place.
It goes partway down reverses direction and goes back up again.
If it closes before that distance has been traveled it thinks something is wrong and it reopens to help prevent any damage or safety risk.
This is almost always the result of a dirty.
But changes in weather conditions can causes your garage door components to shift or contract.
They are usually on the motor housing and you access them by opening a panel or removing the housing cover.
Your garage door is programmed to travel a certain distance before it closes.
These garage doors have sensors near the ground to ensure nothing gets stuck underneath the door when it closes.
Scan the safety sensors.
If the garage door does not close completely or begins to close and then opens back up again the down limit switch needs.