Limit switch or travel limit is one of the many components of a garage door opener that help ensure optimal and smooth operation.
Because it plays a crucial role, any malfunction of the garage door limit switch can significantly affect the working of the opener. Thankfully, you can easily make out and resolve these problems if you know where to look and what to do.
Read along to learn how you can diagnose and resolve the common garage door limit switch problems and save on the cost of hiring a technician.
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What is a garage door limit switch?
As the name suggests, the garage door limit switch is a component on your garage door opener that electrically limits or controls the extent to which a garage door can travel while opening or closing.
The limit switch stops the movement of the garage door when it reaches its fully opened or closed position. It instructs the motor to stop running once the door has reached its fully open or closed position.
Each garage door opener has two limit switches—one for controlling the opening and another for closing.
You will often find the name up-limit switch to refer to the switch limiting how far the garage door can travel when opening, and the down limit switch that controls the door’s closing.
How does the limit switch work?
Understanding how the limit switch works is essential to understanding the common problems likely to keep it from performing its role properly.
Limit switches are located on the garage door opener tracks. In some models, the switch typically looks like a knob. In other models, the limit switch is incorporated in the garage door opener mechanism.
Each limit switch features an actuator mechanically linked to an electrical switch. The limit switch is designed to cause an electrical connection to make or break once an object contacts the actuator.
In the case of a garage, the object that contacts the actuator is the garage door traveling along the tracks. As soon as the door reaches the end controlled by the switch, it activates the actuator through physical contact, gesturing the motor to stop the electrical connection. Once the door reaches its fully open position, it applies physical force to the up-limit switch actuator, signaling the motor to stop.
On the other hand, when the door reaches its fully closed position, it applies physical force to the down-limit switch actuator. This actuator then mechanically activates an electrical circuit that signals the motor to stop running
What does the limit switch do on a garage door opener?
The limit switches form one of the kernel parts of a garage door opener and are used to adjust the function of your garage door. The switches command the opener’s motor to open and close the garage door. These switches come as a pair comprising of a down switch and an up switch.
Bearing in mind that garage doors and garage door openers are not universal, the location of the limit switches is not necessarily in a fixed position. But typically, they appear as two white knobs positioned on the garage door tracks.
What about in chain drive garage doors, you ask? Placed on the top of the unit as two small switches are the limit switches that are activated when the tiny rollers linked to the chain move into the system.
By now, you can surmise that the limit switches control the extent to which a garage door can move while shutting down or opening. They oversee the controlling electrically and play a central role in instructing the garage door to stop while in operation. For instance, upon recognizing that either an object like a bicycle or even a kid is present beneath the garage door, the limit switches come into play by giving instructions to the motor triggering the garage door to stop. The essence of such commands by the limit switches is to promote optimal safety for the user, kids, or objects in the garage’s door pathway.
The practice helps avoid accidents, injuries, or damages that would otherwise result from the heavy garage door closing in on an object or person that was in its way.
Common garage door limit switch problems
The proper working of the garage door limit switches mainly depends on their setting and position on the tracks.
If the close-limit switch is set incorrectly, it may prevent the garage door from going all the way down or closing at all. This means it could cause the opener to pull the door back up or reverse it when you attempt to shut it. Such malfunctions could present a safety concern as the door can close in on someone accidentally.
Here are the common garage door limit switch problems and what you can do in each case.
The supplies you will need
- Step ladder
- Measuring tape
- Flat blade screwdriver
The garage door does not close all the way down
The close-limit switch instructs the motor to stop once the door reaches its fully closed position. If this limit switch is set wrong, it may signal the motor to stop prematurely before the door reaches all the way down. If you experience this issue with your garage door, you can quickly fix it by adjusting the close-limit switch.
Start by closing your garage door the way you typically do—either with the garage door remote or using the keypad. When the door stops, use a measuring tape to measure the distance from the bottom of the garage door to the ground. Record this measurement somewhere in inches.
Various garage door openers have different ways of adjusting the set limit switches. This information should be available in your user manual. However, since most openers will simply require turning a screw feature on the motor unit to adjust how far the door descends, this section will walk you through it.
That said, use a flathead screwdriver to turn the adjustment screw on the down limit switch counterclockwise. The screw should be on the garage door opener side.
Every one full counterclockwise turn should correspond to three inches that you need the door to lower and close all the way down. You can divide the number of inches you took by three to get the number of turns you must make on the screw.
Once done, open and close the garage door again to test if the problem is solved. You may have to continue adjusting the screw further if the problem persists. Ensure you do this until the door operates normally.
The garage door does not open all the way up.
If the door stops before reaching its fully open position, the up-limit switch may need to be moved toward the opener’s motor unit to fix the problem. This switch is typically mounted on the end of the garage door opener track near the motor unit. If it is too far from the unit, the door will stop before opening fully.
Start by opening the garage door with your remote or keypad to fix this problem. Next, measure the distance from the bottom of the garage door to the top of the garage door opening. Note down this measurement in inches.
Climb a stepladder to reach the up-limit switch on the tracks. Once you access the adjustment screw on the side of the garage door opener, use a flathead screwdriver to turn it clockwise. Again, one full turn of the screw should correspond to a 3-inch movement toward the motor unit.
This movement toward the motor unit also corresponds to the distance the door will move to open all the way. So, divide the number of inches you noted down by 3 inches to know how many turns of the screw you will need.
Once done, test the door to see if the problem is solved. If it still does not open all the way, you will need to adjust the limit switch some more until the problem is gone.
This problem is uncommon and will typically show itself immediately after installing a new garage door opener. So if you are installing one by yourself, this would be the time to adjust the limit switch.
The garage door closes and reverses to the open position
If the garage door closes and then begins to open by itself when you attempt to close it, you need to adjust the close limit switch.
Only a few turns of the adjustment screw on the side of the garage door opener should fix the problem. So, use a flathead screwdriver to turn the down-limit switch adjustment screw clockwise once, then test if the door closes properly.
If the problem persists, keep making the clockwise turns in small increments and testing until the door stops reversing upon touching the ground.
The garage door opens, but the motor won’t stop running
This is a problem associated with the up-limit switch being too close to the garage door opener’s motor unit. It is another uncommon garage door limit switch problem that will not just happen out of nowhere.
If it occurs, you will often notice it immediately after installing a new opener. And when that happens, you can typically fix it and forget about it as it will be unlikely to recur over time.
When your garage door opens but the motor keeps running, you may need to move the up-limit switch away from the motor unit.
While the problem is rare and unlikely to occur from time to time, it can still occur in case the gears inside the motor unit have been stripped, causing the unit to run freely without pulling the door.
However, you will only know the problem is related to a defect in the gears after trying the first fix: moving the limit switch away from the motor unit.
If the problem persists after adjusting the position of the up-limit switch, you may have to contact a technician to check the motor unit for you
The garage door reverses immediately after hitting the ground
Suppose you find that when you attempt to close your garage door, and it opens back up immediately after touching the ground, this suggests that there is an issue with the close limit switch. The close limit switch is put in place to help avoid accidents caused by the door closing in on people or objects. Incorrect setting of the close-limit button can manifest as this pertinent issue.
Fix tip: Locate the close-limit adjustment screw fitted on the door opener motor. Proceed to make adjustments on the screw in slight additions till the garage door stops upon hitting the ground.
The garage door reverses before touching the ground
Corroded or ruined rollers can be suspected if the garage door ascends even before hitting the ground because of additional friction. Maladjustment of an adjustment screw part of a garage door opener can also result in this problem. This screw plays the role of regulating the descend magnitude of the garage door before the motor shuts down.
Fix tip: Make an effort to repair ruined rollers or lubricate corroded rollers. If the issue does not lie with the rollers, correctly adjust the close-force settings via the adjustment screw.
How do you adjust a limit switch?
Limit switch adjustments help restore normalcy in its operation. However, if you are a new garage owner or experiencing switch problems for the first time, you may fret finding an appropriate measure to take when you encounter the limit switch adjustment issue.
Elucidated below are steps you can employ to fine-tune the limit switches in an attempt to make adjustments.
Locate the limit switch
The differences in garage door models bring about a variation in the location of the limit switches. Usually, they appear like two white knobs on the door tracks.
Execute the adjustments
Use a flathead screwdriver to make adjustments on these switches after you have identified them. Here is the principle, to add the travel distance, you should turn the knobs clockwise.
To decrease the travel distance, turn the knob in a counterclockwise direction. Proceed to make adjustments through the knobs till you succeed in setting the intended performance. Torsion and weight are vital factors that you should bear in mind when dealing with a garage door.
Test for sensitivity
This test aims at determining the safety force that makes the door reverse while shutting down after you put in pressure. You conduct the test by placing lumber beneath the door or grasping the door while it is closing.
Use the limit screw to make adjustments to the safety force by turning the screw clockwise. Proceed to make the adjustments while testing until you achieve the safety force required.
Add more functionality-increasing features to the door.
Integrating a keypad into the garage door opener is a feature that will reliably increase the functionality of your garage door. The keypad enables you to manipulate the door if there is an emergency or from outside the garage by keying a code in. Another excellent feature is a sensitivity sensor that notifies you when your car is too close to the wall.
The video below shows how to replace a genie garage limit switch when faulty
How do I know if my limit switch is bad?
Inappropriate handling or wearing out of the limit switches after outliving their lifespan are some of the reasons that your garage door limit switches may not be working.
A garage door that reverses midway while it descends or a door that opens and closes improperly shows a problem with the garage door limit switch. To determine if the case is marginal, you can test your garage door by opening it and observing it as it opens and shuts down. If it halts midway, you can correct this by adjusting the up switch.
Garage Door Limit Switch Problems -FAQs
How do I reset my garage door limit switch?
Start by locating the limit switch adjustment screw on the side of the garage door opener. Next, use a flathead screwdriver to turn it counterclockwise or clockwise one full turn for every 3 inches depending on the adjustment you need to make.
How do I know if my garage door limit switch is bad?
Two of the most common telltale signs of a malfunctioning limit switch are: the garage door won’t open or close all the way, and the door opens again immediately after reaching the ground. Such a malfunctioning limit switch can be inconvenient and dangerous, thus requiring prompt action.
Conclusion
Incorrectly set limit switches can prevent your garage door from reaching its fully open or closed position or cause the opener to reverse when you attempt to close the door. While these problems may be inconvenient, they are typically easy to fix without requiring the help of a professional.
Next time you encounter a limit switch problem, feel free to use this tutorial to guide you through fixing it.