Temperamental garage door

February 6, 2013 10:33 AM

Starting a couple of weeks ago, our automatic garage door sometimes goes down about 1/5 of the way and then goes back up.

There aren't any visible obstructions, and there doesn't seem to be an obstruction sensor anyway (the garage door was installed when the house was built, and that was before such sensors became mandatory). The problem only happens roughly half the time we close the garage door (needless to say, regardless of whether operating it from the button inside the garage or from a remote control) and seems random (day or night, hot or cold weather, etc.). When it happens, the only way we can get it down (aside from multiple re-tries) is to stop it when it's going back up and then from that not-all-the-way-up position command it to go back down again. For some reason, if it's not going down from its fully up position, it never fails to go all the way down. Any ideas what could be causing this and how to fix it?

Note that I read this similar thread but the difference is in that situation the door was going all the way down and then back up, whereas ours is just going down about 1/5 of the way before it goes back up. Looking at the answers in that thread, that seems to be a significantly different type of situation.

posted by Dansaman to home & garden (16 answers total)

Check very carefully around the sensor. This happened to us when I was a kid, and the culprit was a spider who had built his web around the sensor. Every once in a while, a breeze would hit just right to blow enough of the web in front of the sensor to trip it. Or the spider would mosey on by.
posted by phunniemee at 10:37 AM on February 6 [1 favorite]

Have you checked the track and the door itself for a slight bend or dent everywhere? Have you checked the chain for a slight bend or dent along its entire length? 1/5 of the way down seems like an odd place for something to have suddenly gotten damaged, so it might be somewhere else entirely, but it does something that catches the mechanism enough at that particular point to trigger it.
posted by Etrigan at 10:39 AM on February 6

Nthing the sensor. We found that the angle of the sun shooting directly onto the sensors did it.

My parents had a similar problem and their only solution was to replace the whole apparatus. Hopefully yours won't require such heroics.
posted by Leezie at 10:40 AM on February 6

Unlatch the garage door from the opener mechanism and run the door up and down by hand to feel for catches. You may just need to grease the track.
posted by jmsta at 10:41 AM on February 6 [2 favorites]

It may not have a beam break sensor but likely it has a force sensor. If the door encounters too much resistance it will reverse itself and go back up. If it is a screw-drive type door you may need to grease the screw drive mechanism as well.
posted by jmsta at 10:46 AM on February 6 [1 favorite]

There are a few things that could be happening, depending on the type of opener you have. Is this a chain-drive, or screw-drive opener?

• If it's a screw-drive, it may be something as simple as the screw needing lubed. There's usually a specific type of grease used for these.
• There are also limiter switches at the front and back of the drive track that may be failing for some reason.
• On the back of my opener's motor housing is a clutch adjustment knob. This can sometimes go out of adjustment, resulting in a door that does not fully open/close.
posted by Thorzdad at 10:46 AM on February 6

In addition to everything mentioned above (all good starts and probably more likely than what I'm about to suggest), you should check:
- If it's a chain-drive, is the chain loose ? (There's usually a double-head screw brace to tighten the chain)
- Are all the connections to the door secure ? (Part that holds rollers on each side of the door, J hook that connects to drive, etc)

That said, I'd lean towards mis-aligned sensors or grease/track-alignment.
posted by k5.user at 10:52 AM on February 6

I just had my door serviced and I talked about this very problem with the technician (he was actually out to replace a broken cable but I have the same problem you do, just not often enough to bother me). All of the above suggestions can cause the issue you describe; in my case he felt it was the force adjustment and messed around with it until the door seemed to shut without stopping. He said that is sometimes a problem in cold weather when the mechanism becomes more stiff and the door needs more force to close. In case you are wondering the service call for something like that is about $80, at least where I live, so it may be worth it to get a professional out there if you try all of the above suggestions and eventually give up. (I would definitely try to fix it myself, though; the only reason I had the repairman out was for the cable.)
posted by TedW at 10:55 AM on February 6

the garage door was installed when the house was built, and that was before such sensors became mandatory

I missed that the first time around; I am guessing that means the opener is at least 20 years old. It may well be time for a new opener. I have installed a couple in my house and if you are reasonably handy it can be done in a half-day or so. Hopefully one of the other suggestions will solve your problem, though.
posted by TedW at 11:00 AM on February 6

You could also have a spring occasionally binding, though I would expect you to have issues going up if the problem was with a spring.
posted by Thorzdad at 11:01 AM on February 6

Ours does this at certain times of the year when the sun is at the wrong angle and shining pretty much directly on the sensor. We checked for everything else mentioned here but in the end the only way to get it to work is to stand between the sun and the sensor cast a shadow on to it.
posted by wwax at 11:07 AM on February 6

If you can raise and lower it by hand without a struggle, look on the unit for a closing force limit control (a little screw usually).

You might want to unplug it and open up the housing to see if there's a lot of white plastic shavings from the drive cog. If you find that, it's toast. Replacing the opener isn't a big deal though because all the mounting hardware has stayed sort of similar over the years.
posted by bonobothegreat at 11:23 AM on February 6

I've seen a similar problem when the arm attached to the spring (i.e. the bit that links the door to the spring) had rotated. This was because some of the bolts holding the arm to the door had weakened and allowed the arm to partially rotate. This was enough to increase the stress on the motor which stopped it from coming down.

The rotation wasn't particularly obvious (probably only about 10 degrees or so) but you could tell if you compared one side to the other.
posted by Mattat at 11:23 AM on February 6

This happened to me. I had a dust bunny hanging from the bottom of the door, and the dynamics of it were just right that it would wave in front of the little proximity sensor that detects whether someone is standing in the doorway and causes the door to automatically go back up. Make sure there is nothing waving in front of that sensor.

(In my case, the dust bunny was a barely visible wisp of junk.)
posted by Doohickie at 12:37 PM on February 6

The opposite of this happened to me recently, as the weather turned colder: our door started stopping about a quarter of the way up when opening it. I put a band-aid on the problem by giving the opening force limit control a slight turn, so that the door can open with slightly greater force. You could probably do the same with the closing force limit control. If you have to make a big change, to the point where you risk injuring a child or animal that gets stuck below the door, then it's time to replace the opener.
posted by brianogilvie at 4:19 PM on February 6

I too would guess that the weather has changed the dynamics of the door such that it is hitting some kind of force limit. And houses just settle sometimes creating bad geometry on things that used to be square. It could also be something like counterbalance springs that have gone out of adjustment.

I agree that the first step should be to pop the handle off of the opener and test the door by hand. It should move fairly easily. Meaning a healthy person of average strength should have zero trouble opening and closing it by hand. If that tests out good, then I'd wager that the opener is just worn out.
posted by gjc at 6:02 PM on February 6 [1 favorite]