Comments on: Help me diagnose my automatic garage door opener weirdness

Question: Help me diagnose my automatic garage door opener weirdness

misskaz — Fri, 22 Feb 2013 09:47:56 -0800

I have a two-car garage with a LiftMaster automatic garage door opener that is misbehaving and it's driving me crazy. It seems to be randomly just opening the door long after it is closed and I can't figure out why. I've seen the other questions about garage door openers but was hoping for some advice specific to my situation.

Relevant or not relevant details:

1. The garage is a detached, unheated, two-car garage (in Chicago, so it's on an alley, not the street.)
2. My roommate and I each have remotes that we keep in our cars, although previously my roommate was keeping his in his backpack. He thought maybe he was accidentally bumping the button so he started keeping the remote in his car but it's still happening.
3. It's not that something is triggering the safety sensor as the door is closing - we are both making sure the door is COMPLETELY closed before driving away or going inside.
4. My roommate even checks the door again before going to bed and sometimes it has opened back up and sometimes it hasn't. Sometimes it is open in the morning, sometimes not.
5. It's one of the self-learning ones so there are no dipswitches to change if someone else's opener is interfering with ours.

Theories we've considered and/or correlating factors:
1. When I bought the house, our house inspector said the safety sensor wasn't working so we should get it fixed, which we never did. Is it possible it can malfunction in such a way that it opens the door long after it is fully closed?
2. My roommate seems to think it has something to do with the neighbor with a garage across the alley -- who does not have an automatic opener but does spend all hours of the day/night working in his garage blasting really loud music.
3. There seemed to be a pattern of my car always being home when it happened, but I don't drive very often so it's almost always home, and then it happened once when I was away.
4. This only recently started happening in the last few months. Coincidentally, I just got a roommate a few months ago - previously it was just my car.
5. Also coincidentally, the last few months mark winter and cold weather.
6. My next door neighbor drives a tow truck and therefore uses some kind of dispatch radio/CB/walkie-talkie thing.

Have you ever had this happen? Any ideas for what we could try to diagnose and/or fix it? I'd love to try some troubleshooting before calling someone out to fix or replace it.

By: MonsieurBon

MonsieurBon — Fri, 22 Feb 2013 09:50:02 -0800

Have you just added any home automation devices, like X10 or Insteon? I added some X10 devices to a circuit that is shared with the garage door opener and it started opening the door at 3am.

By: Confess, Fletch

Confess, Fletch — Fri, 22 Feb 2013 09:54:38 -0800

It's not that something is triggering the safety sensor as the door is closing...

Check to see if there is dirt or cobwebs partially blocking the sensor.

By: Chocolate Pickle

Chocolate Pickle — Fri, 22 Feb 2013 09:55:52 -0800

Most garage door openers have a panel of slide switches in which you enter what is supposed to be a random number. There's another inside the remote control. The main purpose of this is to prevent the door from opening when a neighbor with the same model opens his door.

If there are two openers within close range which have the same number in the slide switches then that will still happen. I suggest you look at the opener and the remote control to see if there's such a package of slide switches (or maybe a rotary switch, or something similar). If so, try changing the setting (on both, to the same thing).

By: Ruthless Bunny

Ruthless Bunny — Fri, 22 Feb 2013 09:57:49 -0800

It's possible that your garage door opener is on the same frequency as another in the neighborhood. (although this would only be the case if your opener was pretty old and didn't have up-to-date technology.

Call the manufacturer and ask them, they may have some ideas.

By: readery

readery — Fri, 22 Feb 2013 10:03:20 -0800

I've had a problem like this as had my mother. In both cases, we drove up and down our alleys pushing our openers seeing whose garage door opened. Then you know if someone has the same frequency. Then it's a matter of someone changing their internal code.

Playing 'What's the Frequency, Kenneth' while doing so, optional.

By: me3dia

me3dia — Fri, 22 Feb 2013 10:04:05 -0800

I agree with Chocolate Pickle and Ruthless Bunny -- someone else may be on the same frequency as your opener. Flip a switch or two and see if that helps.

By: misskaz

misskaz — Fri, 22 Feb 2013 10:07:10 -0800

Just a quick follow up because it was probably lost in my wall of text question:

This is not the kind of opener that has dipswitches to flip. It is a rolling code/self learning newer model. My roommate and I already looked for switches and there are none.

By: Doohickie

Doohickie — Fri, 22 Feb 2013 10:07:51 -0800

1. When I bought the house, our house inspector said the safety sensor wasn't working so we should get it fixed, which we never did. Is it possible it can malfunction in such a way that it opens the door long after it is fully closed?

6. My next door neighbor drives a tow truck and therefore uses some kind of dispatch radio/CB/walkie-talkie thing.

These two jump out at me as potential causes.

Check to see if there is dirt or cobwebs partially blocking the sensor.

I've had this happen to me. It could be that the sensor is being blocked/triggered by something that shows up after you close the door, and activating the opener. I had a dust bunny clinging to the weather seal at the bottom of the door and it would flip up right into the path of the sensor when I tried to close the door. It would go halfway down, then reopen. I'm not sure how the logic works when the door is fully closed, though, and whether that sensor is disabled.

Most garage door openers have a panel of slide switches in which you enter what is supposed to be a random number.

That's already been eliminated: "It's one of the self-learning ones so there are no dipswitches to change"

My thought is this: If when you got your new roommate, you programmed the remote, you may have also inadvertently programmed another remote in the neighborhood (i.e., someone else was pushing their button at just the right time), and when they open their door, yours opens too. Is there a way to completely wipe all the codes and start fresh? If so, try that.

By: pocams

pocams — Fri, 22 Feb 2013 10:34:25 -0800

A friend of mine had this exact problem and it turned out to be a wiring problem with the button in the garage, where the wires running from the opener to the button were messed up inside and shorting out occasionally. I would try disconnecting the wired-in button right at the opener, if possible, to rule that out.

By: randomkeystrike

randomkeystrike — Fri, 22 Feb 2013 10:46:40 -0800

I believe in a corallary to Occam's Razor that goes something like "if you KNOW there's a problem somewhere, sort it out before worrying about what ELSE might be causing another problem somewhere else."

If you know the safety sensor isn't working right, fix it. I'd be willing to bet that there's some relationship there, despite the delay in it going off.

By: beagle

beagle — Fri, 22 Feb 2013 13:11:49 -0800

Power surges will do this too. Sometimes garage doors open and close randomly in thunderstorms. You could try plugging the unit into a surge-protection power strip.

By: advicepig

advicepig — Fri, 22 Feb 2013 13:57:09 -0800

This happened to us for a while and it turned out to be a short in the wire to the button you push to open the door.

By: easily confused

easily confused — Fri, 22 Feb 2013 16:45:47 -0800

Slight derail: just for safety's sake, make sure you always lock your cars anyway, even though they're parked inside the garage. And, of course, all the usual 'don't leave anything valuable in sight' stuff, too.

By: dacbeerpig

dacbeerpig — Mon, 25 Feb 2013 08:17:26 -0800

Our garage door also used to open up randomly on its own.

After confirming we weren't crazy, the problem was traced to wires expanding and contracting with the temperature. There was no slack in the line, so a connection was shorting. Slack was added and the problem went away.