The mystery of the open garage door

January 25, 2008 6:37 AM

Why did I find my garage door open this morning? I haven't opened it with the garage door opener entry pad for several days, and I know it was closed completely the last time I used it.

I have a detached garage off my back yard. (Lined up: house, back yard, garage). There is a standard door leading from the yard into the garage, but the main garage door can't be seen from the house because it is on the other side. So I can't easily see if the garage door is open or closed unless I walk around there and look.

I had a Chamberlain Whisper Drive installed last year that uses a rolling code transmitter. I generally open the door by either pressing the large button on the wall after entering the garage by the door leading into my backyard, or by entering my code into the keypad by the garage door itself.

But this morning I found the door wide open (Luckily, my bike and a few other valuable items were still there.) I don't have a car, so I don't go out to the garage daily, so the door may have been open for minutes or even days, as the last time I opened the garage door was Monday night.

So far, my theories are:

1) The small remotes stored in my back room may have been nudged so that the open buttons were pressed.
2) Someone guessed the correct code, opened my garage -- and took nothing.
3) One of my neighbours' remotes somehow opened my door, but given the rolling code, isn't this astronomically unlikely?

Any other theories? And what steps should I take to prevent this from happening again?

It would be fast and easy to change the code on the keypad, if this was somehow compromised, but I may have to actually clear all codes to make sure the small remotes are cleared, too, and only reprogram the keyless pad. (Remember, I don't drive and don't need the remotes, although I want to keep them if I sell the house so the new owner can use them).

posted by wexford_arts to home & garden (20 comments total)

Ask the company who supplied / installed it if this is a common problem and if they have any non-expensive remedies. They may recommend you change some switch on the remote (if any) or at least give you some explanations. They may also have a way you can temporarily disable the ability for the remotes to open the door and just use the key pad.

Do you live near any military bases, airfields, etc? I've read quite a few news reports over the years of groups of people having issues with things like car alarms, garage doors, etc, who live near military complexes.
posted by wackybrit at 6:41 AM on January 25

You might have a short in the wiring. We had this problem with our Genie opener, but only in extreme heat.
posted by candyland at 6:45 AM on January 25

Sometimes my garage door goes down and then instantly starts to come back up. This has happened without my noticing twice.
posted by waraw at 6:49 AM on January 25 [1 favorite]

My parents have a craftsman door opener that has a wireless transmitter that shows when the door is in the open position...maybe Chamberlain has a similar product?
posted by doorsfan at 6:51 AM on January 25

I have had this happend because of sticking switches in the both wireless remotes and wired wall buttons. It's actually not the switch per se, but the plastic part of the button rubbing against the housing.

On preview: I've had what waraw mentions happen before too. This was fixed by moving the switch that signals the end of door travel about 1/4" toward the motor.
posted by probablysteve at 6:54 AM on January 25

This happened several times to me recently. It turned out to be a remote stored in a kitchen drawer that would activate sometimes when someone was rummaging through the drawer. If you have the new rolling code type it is highly unlikely that your neighbor's remote opened your door.
posted by caddis at 6:54 AM on January 25

Wow -- you guys are fast!

I'm not near any military bases, airfields, or even any UFOs.

I'm paranoid about the door closing completely, so I watch for a couple of seconds after it closes.

I phoned up the support line for Chamberlain and the tech had me check for a short (no flashing lights, so no short). He said that if there was no short, it was possible that a neighbour's remote may have opened my door. Like caddis, I find this very unlikely.

I'm going with the accidental button impact/rummage theory for now. The tech walked me through clearing all the codes, then setting them only for the keypad, so I'll do this later on today.

Thanks!
posted by wexford_arts at 7:02 AM on January 25

Door openers are very sensitive to weight and resistance. It could be that because of a change in the weather the door did not close the last time you thought you closed it. If you just hit the button and walked away it could have at some point during closing sensed too much resistance and triggered the safety that reverses, and thus leaves it open.
posted by Gungho at 7:18 AM on January 25

has happened to me several times - after installing a security light nearby that uses a wireless motion sensor and wireless push button activator. Scrapped the light (it sucked anyway) and went with a hardwired unit, and the problem went away. What the experience taught me is that these door openers are not immune from interfering signals that can cause the door to open. Try changing the frequency for starters, then go from there. I know how you feel, I'd come home to my not so great neighborhood to see my garage door wide open, with all my tools, bike, mower etc exposed! no one ever took anything so that made me feel better tho.

have not had a problem since switching out the motion light. talk to neighbors, see if they recently installed anything like this
posted by Salvatorparadise at 7:24 AM on January 25

I haven't seen any new security lights or garage door openers nearby, but I'll check.

My manual covers changing codes, but not the frequency. Is that something the consumer can even do? From this article, it looks as if 390 is the standard frequency.
posted by wexford_arts at 7:54 AM on January 25

hm, i guess i am referring to the pin switches in main unit...i thought they controlled frequency, maybe someone else will chime in...i believe it's all in the 390 range, but makes slight changes to the frequency in use
posted by Salvatorparadise at 8:03 AM on January 25

I don't think the rolling code types even have dip switches inside anymore. Here is a primer and according to it the chance of a neighbor's remote opening your door is about one in a billion. It was only one in 256 for the old style dip switch remotes though.
posted by caddis at 8:31 AM on January 25

My first thought was a power surge, maybe from lightning?
posted by misha at 8:33 AM on January 25

You never use the remotes? Just remove their batteries. That'll keep them from sending any signals!
posted by exphysicist345 at 9:11 AM on January 25

I tried to remove the batteries in the remotes first thing, but the cases are sealed.
posted by wexford_arts at 9:22 AM on January 25

I put my remotes out in the garage. They are in a logical place to find them if I need them later, and if they are activated there whomever did it will see the door going up. The kids have a habit of leaving the door open after playing outside so I also installed a sensor which sends a signal into a receiver in the house. A red light shows the garage door has been left open.
posted by caddis at 9:50 AM on January 25

Maybe I missed it in the list above, but another possibility is roving packs of curious teens / thugs / hooligans driving mom's car around all day pressing the remote to see who else's garage matches their remote.

Oh, and I read that sunspots are to be more pronounced in the near-term than usual. Maybe ol Sol is playing tricks...
posted by dontrockwobble at 10:11 AM on January 25

caddis, I've considered leaving the remotes in the garage, but you guys have had me reading my manual a lot this afternoon, and I just found a way that the master door opener button beside the yard door can be locked to prevent the remotes from opening the door no matter where they're kept. (The tech on the phone didn't mention that at all.) So that will do until I get the ladder out and deactivate the remotes from the unit itself.

So thanks again for all the great answers. And maybe someone else can learn from this question not just the myriad ways in which a garage door can mysteriously open, but the value of RTFM and calling the manufacturer.
posted by wexford_arts at 10:49 AM on January 25

One thing that people don't realize is that some openers operate on the same frequency as others in the neighborhood - this has happened to me before. Rare, but it happens. A lot of garage door openers have locks on the wall units. We lock ours at night if we know no one is going to be coming home later. You might look into that because it gives us great peace of mind. Good luck!
posted by inquisitrix at 8:14 PM on January 25

One thing that people don't realize is that some openers operate on the same frequency as others in the neighborhood - this has happened to me before.

wexford has a rolling code opener. this is not an issue with those. billion to one odds, or thereabouts. he's more likely to win the lottery than have his neighbor open his garage by mistake.
posted by caddis at 8:30 PM on January 25