1- The door becomes very heavy and only goes up halfway.
The torsion spring(s) has been installed backwards; see step 5.
2- The door opens very fast and is hard to bring back down.
The spring has been wound too much, it is too tight. Adjust the tension. See step 5.
3- The door closes fast and is hard to lift.
The spring has not been wound enough. Adjust the tension. See step 5.
4- The door works well but it goes back up 2 to 3 inches.
The spring is a little too tight. Adjust the tension. See step 5.
5- The door does not close completely flush with the ground.
The flooring isn’t perpendicular with the vertical rails. If it’s a flooring problem, you will have to make a level threshold.
6- The door is hard to open at the beginning of its race.
Move the rollers of the first or second panel. Loosen them and keep them slightly away from the door.
7- The door is hard to open at the end.
The horizontal tracks are not perpendicular with the axis of the door. Use a tape measure to check this out.
8- The top panel does not close completely.
Adjust the position of the upper rollers bracket (upper or lower).