The limit switch is located on the garage door opener housing. The garage door opener limit switch tells the motor that lifts and lowers the garage door when to stop running. Incorrectly set limit switches may prevent your garage door from closing completely or opening all the way. They can also cause the opener to reverse or pull back up when you attempt to close it, which can seem like a malfunction or that someone else is using a garage door opener remote that is on the same frequency as yours. This is actually caused by a safety mechanism meant to protect people from being hit and having the door close on them. Resetting the limit switch will stop your garage door from behaving erratically. Open the garage door and watch it closely as it opens. When the garage door opens about halfway, or 5 feet, from the ground and stops, the up limit switch needs to be adjusted. Measure the height where the door stops while it is being opened. The measurement is used to reset the up limit switch on your garage door opener.
Close the garage door with the opener and watch it closely as it closes. If the garage door does not close completely, or begins to close and then opens back up again, the down limit switch needs to be adjusted. Measure the distance of the gap from the bottom of the garage door to the driveway or floor if the garage door will not close completely. The measurement will be used to reset the down limit switch. Set the step ladder under the garage door opener in your garage and use it to access the up and down limit switch adjustment screws located on the side of the garage door opener motor housing. Turn the up limit switch screw clockwise by one turn for every 3 inches that you need the garage door to raise up with a flat blade screwdriver. This may move the chain trolley of the garage door opener. If it does, leave a 2-inch to 4-inch distance between the cover protection bolt and the trolley. It's the part of the door mechanism that moves the chain that opens and closes the door. Turn the down limit switch screw counterclockwise one turn per every 3 inches of the garage door gap -- the distance between the bottom of the garage door and the driveway when it does not close all the way -- with a flat blade screwdriver.
Turn the down limit switch screw clockwise one turn with a flat blade screwdriver if the garage door closes and then begins to open back up. The garage door will automatically go in reverse whenever it hits an obstruction, such as the driveway or ground. In this case, the garage door opener detects that it is coming into contact with the driveway or the ground and immediately switches into reverse and raises back up as a safety mechanism. Try to close the garage door. If it still automatically begins to reverse or open back up, turn the down limit switch screw clockwise one turn and test it again. Continue turning the down screw clockwise by one turn and testing it until it no longer automatically opens back up when you close it. Things You Will Need Measuring tape Step ladder Flat blade screwdriver Tip References Sears: Craftsman Garage Door OpenerGenie Door: Garage Door Troubleshooting Guides Photo Credits Jupiterimages/Comstock/Getty Images Suggest a CorrectionBack to Garage Door Question List
The first thing to check are the electric eyes that are located on either side of the door frame. Their purpose is to detect an object in the way of the door and reverse or disable the opener. If the eyes are not facing directly at each other, they may work intermittently, causing occasional spontaneous reversals with no rhyme or reason. If you don't have these eyes, no one stole them... you just have an opener that was built before the 90's when they became mandatory for all newly manufactured openers. Disconnect the garage door opener from the door and go through the troubleshooting routine on the garage door repair page. In fact, you really should read the entire garage door repairIt will make troubleshooting later much easier! Remember that sometimes, a garage door opener can increase the binding in a door just because of the way it pushes the door down. Ever notice how it is easier to pull a wagon over a curb than it is to push it?
doors were designed to be pulled, not pushed. You may think the door is working OK because it feels OK, but you should still check all components to be sure. Do any necessary repairs, reconnect the opener and try it out. are having problems, you can make slight adjustments to either the closing force, opening force, or the travel limit adjustments. Some older garage door openers do not have nicely labeled adjustment screws for force and travel limits. In fact, even some of the newer openers manufactured for and resold by your basic garage door company are not userThis guarantees return business... costly minimum charges for diddlyUnfortunately, I cannot give you specs on every opener and all the configurations, but, if you want to know how I have approached the problem of limit adjustments on an unknown opener, it's really a matter of observation and how they work will help you to find the adjustment. on the principle of transferring force to a momentary contact switch:
If there is enough resistance to the movement of the door, this force is transferred back as torsion (twisting force) in the motor assembly. this torsion exceeds the strength or tension in the springs that stabilize the motor assembly, the assembly twists. A small arm of some sort is attached to and moves with the motor assembly. If the movement is great enough, the arm will strike a switch, sending an electrical signal to the The springs and/or switch may be located on the top of the unit, or is off, plug the opener in, keep your hands clear, and send the opener through a cycle or two. If you are lucky, it will reverse as always and perhaps give you a clue as to where the force adjustment springs are. If you figure out where the adjuster is, simply increasing the tension on the spring will increase the closing or opening force. For opening and closing limit adjustment: Look for trip arms or clips attached to the opener chain.
may be metal plates screwed on to the chain, plastic snap-ons dojiggies with flexible metal arms attached, etc. There will be two on the chain, one for the opening limit and another for the closing limit. activate the opener, the clips move with the chain, and hit the auto-reverse switch when they reach it. By repositioning them, the switch that they trigger activates earlier or later, thus increasing or Open up the case and look for a screw-type track that moves when theSometimes, the limit switch is activated by the movement of a specially shaped "nut" traveling on this track. opener is activated, the screw rotates, causing the nut to move, until itWhen the opener reverses, the screw turns the opposite way, and the nut travels back. There may be two nuts on one track... one for the opening limit and one for the closing limit. starting position of whichever nut, the opening and closing limits areYou know what they say... sometimes you feel like a nut... sometimes