A Common Garage Door Problem That Has Several Causes
If your garage door starts to lift and then suddenly comes back down, you are dealing with one of the issues garage door technicians get called about most often. It can seem like the door has a mind of its own, but there is almost always a real reason behind it. Modern garage doors are built with several safety features that stop the door whenever something seems off. A door that reverses on its own is simply one of those safety features doing exactly what it was designed to do. The encouraging part is that most of the reasons behind this behavior are simple to track down and repair. The frustrating part is that more than one thing can trigger the same symptom, so you have to rule them out one by one. The steps below follow the same checking order a trained garage door repair technician would use, which means you may be able to skip a service call if the answer turns out to be an easy one.
Begin with the Safety Sensors Near the Floor
The very first place to look is at the photo eye sensors. You will find them as two small dark boxes attached to the bottom of each side of the garage door opening, just a few inches off the ground. One box shoots an invisible beam across the doorway to the other box. Anytime something interrupts that beam while the door is closing or opening, the door automatically backs up so it doesn't squash whatever it has detected. Step over to the door and take a careful look at both units. They need to be aimed straight at each other with no tilt. Almost every sensor has a tiny indicator light, usually green or red. A green light typically tells you everything is fine. A red light usually points to a blockage or an alignment issue. Inspect the lens for spider webs, dirt, fallen leaves, or any small object resting in front of it. Use a clean, soft cloth to wipe each lens. If the red light stays on after cleaning, carefully tap one sensor a little at a time until both lights show green. Fixing the photo eyes takes care of close to half of the cases where a garage door reverses on its own.
Inspect for Obstructions in the Garage Door Tracks.
If the sensors appear to be functioning properly, the next thing to inspect is the door’s tracks on each side—those metal rails that guide the rollers up and down. Frequently, a tiny object can become lodged in the track, such as a stone, a child’s toy, or a piece of cardboard from a shipped package. When the door lifts, it strikes the obstruction, and the opener interprets the resulting resistance as an unexpected obstacle, prompting the safety mechanism to reverse the door’s motion. Examine both tracks from top to bottom while the door is fully open and clear away any debris. While you’re at it, look for rollers that may be bent or broken, since damaged rollers can also generate resistance that the opener detects as a problem.
Inspect the Door’s Springs
Look up just above the top of the door, and you'll spot one or two long, tightly wound steel coils stretched across a shaft. These components are called torsion springs, and they're responsible for nearly all of the lifting power when the door opens. People often think the motor does the heavy work, but it doesn't. The opener mostly controls the direction of travel. The torsion springs supply the actual lifting force. As the spring ages or fails completely, the door's full weight transfers onto the opener, which was never designed to carry that load. After lifting the door only a short distance, the motor gives out and the door reverses back down. To examine the springs, look carefully along the length of each coil for any visible separation or fracture. A failed torsion spring will almost always show a clean two-inch gap where the metal snapped under tension. Should you discover a broken spring, do not attempt to repair or replace it on your own. Torsion springs store an enormous amount of stored energy, and mishandling one can cause a serious accident. This kind of repair should always be left to a qualified garage door specialist. The typical service call for torsion spring replacement falls in the range of two hundred to four hundred dollars.
Check the Door's Balance Manually
Even if the springs look okay, they might be weakening. Here's a simple test. Pull the red emergency release cord that hangs from the opener rail. This disconnects the door from the motor. Now lift the door by hand. A properly balanced door should feel light. You should be able to lift it with one hand, and it should stay in place when you let go halfway up. If the door feels very heavy, or if it slides back down when you let go, the springs are losing strength. A weak spring is one of the most common reasons a door reverses partway through the lift. Once you've tested, pull the release cord back toward the opener to reconnect it.
Adjust the Force Settings on the Opener
Look at the back of your opener's motor unit and you'll find two small adjustment dials or pushbuttons. One of them sets how much force the motor uses while raising the door, and the other sets the force used while lowering it. As time passes, hardware wears down and temperatures change with the seasons, which means the opener sometimes needs a small boost in force to lift the door properly. When that force level is garage door fixes set too low, the opener mistakes normal resistance for hitting an obstacle, and the safety feature kicks in to reverse the door. Whether you own a LiftMaster, Chamberlain, Genie, or Craftsman opener, the manual for your specific model will point out the exact location of these controls. Turn the up-force dial up by just a small amount, then run the door through a full cycle to see how it behaves. Make changes in tiny increments rather than big jumps. Cranking the force setting too high creates a real safety problem because the opener will keep applying pressure even when something is genuinely blocking the door.
Check out the Travel Restrictions Settings
The opener's travel limits determine the upper and lower points the door should reach. Incorrectly set limits the opener to mistakenly door has reached its reverse its direction. This issue outage, installation of a new opener, or maintenance work on the door. Similar to settings, the controls for adjusting the travel limits are located on the back opener motor. Referring to the manual them a simple task. If the door now travels too high or too low, it indicates a problem with the travel limits that should, even if the door is not completely reversing.
Chilly Temperatures May Trigger the Same Issue
In winter, a stiff and cold garage door can put extra strain on the opener. Old grease in the tracks becomes thick, rollers don't spin as smoothly, and the door becomes harder to lift. The opener works harder, hits its force limit, and reverses. If your door only reverses on cold mornings and works fine the rest of the day, this is probably what's happening. The fix is to clean the tracks and lubricate the rollers, copyrights, and springs with a garage door specific lubricant. Avoid WD-40, which actually cleans grease off rather than adding it. Use a lithium or silicone spray made for garage doors.
When to Quit DIY and Hire a Professional
If you've checked the sensors, the tracks, the springs, the force settings, the travel limits, and lubricated the door, and it still reverses, it's time to call a garage door repair contractor. At that point, the problem is usually inside the opener itself — a worn drive gear, a failing capacitor, or a damaged logic board. These repairs need proper tools and parts. A good technician can diagnose and fix most issues in under an hour, and the visit usually costs between one hundred and two hundred dollars before parts.