Garage Door Does Not Close




Introduction: Garage Door Does Not Close

About: I miss the days when magazines like Popular Mechanics had all sorts of DIY projects for making and repairing just about everything. I am enjoying posting things I have learned and done since I got my first ...

It was late in the evening.  My wife had just come home.  The garage door did not want to close when she pressed the button on the remote.  It had worked just fine a few hours earlier.  My tools are in the garage.  Leaving it open all night is not an option.  

Step 1: Force It to Close?

This is the hard wired switch on the wall.  She was able to make it close by holding the pressure plate on the switch down until it had closed.

Step 2: Signs to Observe

The light on the ceiling mounted opener flashed as she held the wall switch down to close the door.  That is not normal.  

Step 3: The Sensors

This is one of the sensors.  There are two.  One sends a beam of infra-red light to the other.  If anything interrupts this beam of light, the garage door will not close and the ceiling light on the opener mechanism will flash as mentioned in the previous step.  This is, of course, a safety feature to prevent the heavy garage door crushing anyone or anything that might be in the pathway of the door when it comes down.  Check to be sure no child's toy or anything else blocks the path for the infra-red light beam.

The text box feature would not save when I did this Instructable, so I am overlaying colored arrows as keys to my explanation.  

Most garage door problems can be traced to the sensors.  The circuitry inside the sensors is quite reliable and has a long life.  The first thing to check is the mounting brackets (blue arrow).  Did something bend them so the sensors are no longer aligned?  A quick visual inspection of each should be sufficient.  In doubtful cases, you can stretch a long string between the sensors to see better if they are aligned. 

The red arrow points to the LED.  Each sensor has an LED.  It should be bright and show a solid color.  Some are green and some are red, depending on the manufacturer of your opener unit.  One sensor on our unit showed a bright steady LED.  The other, this one, was weak and it fluttered rapidly.  That, together with the flashing ceiling light and the need to hold the switch button, are signs something is not right.

The yellow arrow points to the lens.  It should be clean on both sensors.  This garage is my workshop.  It is always possible sawdust could have accumulated on the lenses.  As a precaution, wipe them with a rag or a tissue.

The green arrow points to the wire that runs between the sensor and the opener unit on the ceiling.  Look for obvious physical damage (bare wires, loose connection, cut or broken wire, etc.)

Step 4: What, Exactly, Could Be the Problem?

We do have a manual for our opener unit, but its troubleshooting section tells you how to check a few basic things, and then says, "You may need to call a technician for repair service."  I am not much in the mood to wait for a technician at the time I want to be going to bed, if I can find one who will come late in the evening.

It has been two years since I had problems with a garage door opener, and that was a different unit than this one.  I forget the procedure for troubleshooting one of these units.  I have come to go on-line for help on the occasions when the garage door opener fails to work.  After a quick search for "garage door opener troubleshooting," I opened this page.  There are some general help pages, but they do not offer much more assistance than our manual and its suggestion to call a technician after checking a few basic things like obstructions to the infra-red beam and power to the circuit.  

Help suggestions are often very brand specific.  The image with this step is a chart for diagnosing problems with the sensors on a Genie garage door opener.  Look closely and you can see that Genie gives diagnostic clues and codes in how many times the LEDs flash and in the color of the LED that shows something unusual.  Our unit is not a Genie, but a Liftmaster.  The help sections for Liftmaster units are more general and not very helpful.  

Step 5: The Solution

I know from past experiences that the electrical connections to the sensor must be good, or the door opener does not work properly.  I had already checked for obstructions to the infra-red beam, for power to the system, cleaned the lenses on the sensors, checked for alignment of the sensors by looking for bent brackets and so on.  I grasped the small plastic plug at the end of the wire and pulled it out of its socket on the sensor.  It required quite a strong pull.  Do not pull on the wire, but on the plug.  It may seem there is a catch that must be released first, but there is not.  When I put the plug back into its socket, the LED no longer fluttered and the garage door worked properly once again.  In time these connections corrode slightly with oxidation.  Breaking and making the connection again is enough to restore its function.  And, I did not need to call a technician.  



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    36 Discussions

    After spending an hour this morning with a garage door that keeps reversing (has been acting funny over the last week) and on live chat with Genie - I finally got the door to go down - and Genie to say that I needed to call in to their help line. Once the door was down I went to the coffee shop to search online help - came across your site/question/answer.

    Thank you! I am now convinced the sensors have something to do with this. Will check when I get home. It is a new opener - month and a half or so - has been working fine. Was thinking it was the door though it was serviced last year and appears fine - operates fine - nothing blocking sensors.

    You have given me something to check. Thanks!

    Thank you for looking. Actually I have a very selfish motive. The next time I have a problem I can refer to my Instructable without doing all of the research again. It is also fun to benefit others now and then.

    We have a large 8' wooden garage door opener with a new Chamberlain opener and the sensors are fine and alligned, but the door opens fine but it will not close? I've tried incresing the power to the down control and still will not close. It gets to a certain point and stops and when you press the button again it goes up and this cycle continues. Please assit if filmiar

    1 reply

    I do not regularly repair garage door opener systems, and can go a number of years between troubleshooting problems with one. When you say yours is new, does that mean it is freshly installed and not working, or does that mean it had been working, but now will not go down? I am guessing the door encounters some form of resistance it interprets as an obstacle it should not crush and it stops. Is something binding? Can you operate the door smoothly by hand when it is released from the opener linkage? While the door is released from the opener linkage does the linkage travel across its normal full range? Those are some things I would check.

    Thanks! Your instruct able made me look like a smart guy. I only wish I had made it seem like an all day job. I finished this in record time, then had to do more on my honeydew list.

    1 reply

    Garage door problems are temporal and finite. Honey dew lists are eternal and infinite. I am glad it was helpful. Thank you for the report back.

    Very informative article. I do have a question for Phil. I have Chamberlain LiftMaster. One of the sensors is not on. Doesn't look like wires can't be unplugged. Should I replace entire sensor? If so should I replace a pair? Thank you

    1 reply

    I am not a professional garage door opener serviceman. The opener on the garage featured in the Instructable is a LiftMaster, and the wire connections to the sensors oxidized so that there was a poor connection. Can yu use a sharp knife to wiggle the very small plug on the wire from its socket in the sensors?

    Thank you sooooo much! I had the same problem and after following your clear instruction. It works!! My garage door opener is working properly now. The problem was the two sensors didn't line up.

    1 reply

    Thank you for your report. I am glad it was helpful.

    That is a tough situation since no one wants to leave their stuff unprotected with the door open. I wonder if there was something blocking the beam at the opening? That would make it so it wouldn't want to close. Checking the springs might be a good idea as well.

    I have a garage door safety beam that blinks when blocked. The garage door rarely works with any button. I checked wires and cleaned the lenses. Any other ideas?

    2 replies

    I have had problems with the alignment of the beam and its receiver from one side to the other of the garage door opening, especially if something bumped it. A long piece of string pulled taught to follow the beam's actual path can be helpful. I also have a laser pointer on a 24 inch household carpenter's level. It is useful for checking up and down as well as left vs. right deflection on the beam. The other problem I have had is making sure the remote and the main unit are programmed to the same code. Rubberized buttons on remotes sometimes lose the conductive coating on the working side and do not make good electrical contact. Of course, the batteries in the remote need to be good. Most problems are due to small things rather than major failures.

    It worked fine after working the plug in its connector on the sensor, and continued to work well. I have since retired and we now live in a different home in another state.

    Nice blog. This is great collection of helpful tips for garage door maintenance and I think everyone can easily use these tips in order to maintain his/her garage door without the need of any professional. I think everyone should read this blog once and apply these tips by itself. If you want more Information visit

    thanks! Turns out I had this exact problem (and model door opener). Sure enough, removed and re-connected the connector to the sensor, and viola! working door.

    1 reply

    Congratulations to you! I am glad this was helpful to you. Thank you for looking.

    Well I have two comments. Great way to show how a simple problem ( corroded / broken contacts ) could and often does lead to calling a technician. But with just a little digging that expense can be avoided. To prevent corrosion in the future you may want to use a dielectric grease on those contacts. Second is I noticed in your response that when the emergency release was used the door was impossible for you to open. This is a problem. The springs should counter the downward force of the door so that a person can open it unassisted. By making sure this is done you reduce the work load the opener has to do. From a safety point the garage can be opened even though no power is available. A fire can knock out power real easy. I'd call a highly rated garage door service and get this fixed. It does not matter what material the door is made of the springs/ counterbalance system should do this job.

    1 reply

    Unplugging and waiting would not have helped in this case. I have not seen the product you mentioned. As they say, anything that goes through the air can be hacked.