Your garage door system has safety sensors that work like safety guards. These devices stop the door from closing on something (or someone) that’s in the way. But when they’re not aligned, you’re likely to encounter the same problem your garage door does when it has misaligned safety sensors: It might refuse to close. And that’s a problem, because you want your garage (and home) to be secure.
If your garage door has been on the fritz lately, reversing when you attempt to close it or with the opener light blinking persistently, the sensors could be to blame. The excellent news? You can usually resolve this issue in half an hour or so with just a few rudimentary tools.
Before we get started, here’s an important safety note: while sensor alignment is generally a safe DIY project, always disconnect power to your garage door opener before working on any electrical components. If you notice damaged wires or feel uncomfortable at any point, it’s best to call a professional.
How Do Garage Door Sensors Work?
Think of your sensors as having an invisible conversation across your garage opening. One sensor sends out an infrared beam, while the other receives it. When this beam gets interrupted—by a person, bicycle, or even a rolling trash can—the sensors tell the garage door opener to stop closing and reverse direction.
Both sensors need to “see” each other perfectly for this system to work. Even a slight misalignment can break their connection, causing your garage door to malfunction.
5 Clear Signs Your Garage Door Sensors Are Misaligned
Recognizing sensor problems early can save you from bigger headaches down the road. Here are the telltale signs that your sensors need attention:
- Garage Door Won’t Close Completely: Your door starts closing normally but then stops and reverses back up. This happens because the sensors think something’s blocking the path, even when nothing’s there.
- Sensor Indicator Lights Are Red, Blinking, or Off: Most sensors have little LED lights that indicate their status. A steady green or amber light usually means all is well. Red, blinking, or no lights often signal alignment issues.
- Door Reverses Immediately When Closing: The door hardly shifts downward before it reverses. This instant reversal often means the sensors cannot establish their infrared connection at all.
- The garage door opener light blinks continuously: A lot of units have a diagnostic light that blinks in certain patterns to indicate certain problems. Check your owner’s manual to see what the different blink patterns mean for your model.
- Remote Control Becomes Unresponsive
Although this may suggest different problems, remote operation can sometimes be hampered by sensor problems, particularly when the system has safety protocols in place that prevent any sort of operation in the event of sensor failure.
Tools and Materials Required to Align Garage Door Sensors
Before starting the alignment process, gather these items to make the job go smoothly:
Essential Tools:
- Phillips head screwdriver (most brackets use Phillips screws)
- Level (at least 2 feet long for accuracy)
- String or fishing line (about 10 feet)
- Electrical safety gloves
- Measuring tape
Optional but Helpful:
- A friend or family member to assist
- Flashlight for better visibility in darker garages
- Small brush or cloth for cleaning sensor lenses
Garage Door Sensor Alignment Checklist
Now, let’s walk through the process and find out how you can align the garage door sensors. Take your time with each step, rushing often leads to mistakes that require starting over.
Step 1: Disconnect Power Supply
Go to your electrical panel and find the circuit breaker for your garage. Turn it to the off position. If your garage door opener is plugged into a ceiling outlet, be sure to unplug it as well. Now, test that the power is really off by trying to operate your garage door. Press the wall button or remote—you should get no response.
Step 2: Examine Current Sensor Position
Inspect both sensors carefully. Examine the mounting brackets for any apparent damage—such as cracks or bending that would indicate a severe impact. Any debris—like spider webs, leaves, or dirt—that’s blocking the sensor lenses should be completely removed. Sensors should typically be 4-6 inches off the ground. Make a mental note of the current height.
Step 3: Loosen Mounting Brackets
Using your screwdriver, turn the bracket screws counterclockwise just enough so that you can slide the sensors up and down. Don’t take the screws out—you want the brackets loose enough to not be in the way when you adjust the sensors, but still holding the sensors in place. Test that both sensors can move freely within their brackets.
Step 4: Position Sensors at Base Level
Carefully move both sensors to the bottom position allowed by the brackets. This gives you a consistent starting point for alignment. Make this adjustment with your hands only—tools might mar the sensor housings. Now, both sensors are at approximately the same height.
Step 5: Create Reference Line
This is where that string is useful. Securely fasten one end around the first sensor and its bracket. Stretch the string across your garage opening, keeping it taut. Fasten the other end securely to the second sensor and its bracket. You now have a visual reference line to help ensure both the first and second sensors are aligned at the same height.
Step 6: Level the Sensors
Set your level directly under the string and lay it on the garage floor. The centered bubble will indicate that the string (and therefore your sensors) is perfectly horizontal. If not, adjust one sensor up or down until the bubble centers over the level. Check from several points along the string to ensure that it didn’t bubble center just for the place you looked.
Step 7: Secure the Brackets
Once everything finds its level, the sensors can be fixed in place. Each sensor must be steady while the bracket screws are drawn taut. The screws should be turned clockwise until they reach the snug level—neither too loose nor too tight. The latter, of course, is what we worry about; if we overtighten now, we can damage the sensors. We shouldn’t go past that point.
Step 8: Secure the Brackets
Without bumping the sensors, carefully untie and remove the string. This is a good time to clean the sensor lenses with a soft cloth. Even a thin layer of dust can interfere with the infrared beam. Now, ensure that both sensors still point directly at each other across the opening.
Step 9: Test and Verify
Now that the sensors are aligned, it is time to see if your hard work has paid off. Restore power by flipping the circuit breaker back on and plugging in the opener if necessary.
Check the indicator lights on each sensor. The majority of systems demonstrate a steady green or amber light when the sensor is properly aligned. If you observe red lights or blinking lights, the sensors still require adjustment. Some models use different light patterns, so consult your manual if you are unsure.
Check the door by putting it through several full cycles. Use your remote or wall button to open and close the door fully at least three times. The door should function properly in that it should not reverse or hang up during a closing cycle.
For the crucial safety test, place a cardboard box or rolled-up towel in the door’s path while it’s closing. The door should immediately stop and reverse when the object breaks the sensor beam. Never use body parts for this test.
If the door still won’t close properly, double-check that both sensors are clean, secure, and have steady indicator lights. Sometimes a tiny adjustment—just a hair’s width—makes all the difference.
When to Contact Professionals
Although sensor alignment is often a clear-cut DIY job, occasionally the task requires a pro’s touch. If you’ve attempted to line up the sensors more times than you can count and still have a nice, clean result that stays put, then you might need to ask yourself whether what’s at issue is you or the system.
Wiring that is damaged necessitates prompt expert care. Never attempt to splice or repair sensor wires yourself. This creates dangers of fire and shock. Likewise, if the sensor housing has cracks in it or the mounting brackets are dangerously damaged, getting replacement parts and having them installed by a pro guarantees there won’t be safety issues.
Garage door systems with many intricate safety features could have sensors that work with other components of the system. These systems—when the modern offspring of a 1950s hand-crank door, if you can believe it!—often require just-this-side-of-superhero adjustments to keep them from being dead or dangerous.
If you have sensor issues that just won’t go away or see any indications that your sensors are electrically damaged, then let Easy Garage Door Repair come to the rescue! Our technicians in the Houston area are experienced with garage door sensor repairs, and we can do them right and do them quickly, oftentimes on the same day you call us. We serve the areas of Sugar Land, Katy, Pearland, Cypress, and the communities around these areas, and we can serve you next!
