West Valley garage door frequencies mysteriously jammed

There are actually neighborhoods that are near airports, that used to have a lot of garage doors start opening when planes would fly overhead, from stories that I have been told by a former coworker. I wouldn't chalk it up to any kind of conspiracy in this particular case, most likely just interference.

reply to post by deadlysyn


Interference shouldn't cause a door to open. The remotes have a code, and it is pretty unlikely the code will be transmitted by the aircraft. Interference will prevent a lock from working, but it shouldn't open a door.

The newer garage doors have rolling codes. That is, you don't send the same coded signal over and over, but send a signal that can be found in a pseudo random number sequence. That makes it impossible for devices that sweep through all codes to open the door.
Most car door key fobs work this way.

I have been a garage door technician for many years and this is a known issue. In 2005 they started making operatos that would work on a different frequency. It is a common problem with older Liftmaster/Sears Craftsman/Chamberlan and a few other brands. If you are having this problem it may be time to update your garage door operator. I would also have them make sure you springs are still in good shape and not worn out. Keep your garage door in good working order for your familys safety. Thanks and have a great day!

reply to post by gariac


Except, somehow, from what I was told (I wasn't actually in the door business when it happened), it was happening. Again, this is only what I was told, and never actually got to see it for myself. Believe it or not, I can actually set up a homelink in a car to open multiple doors, off the same button, without programming that button to more than one of those operators. In other words, the rolling code is a great technology, but it isn't perfect. I know this because I had it happen programming up the homelink in a BMW to a garage that had 4 doors in Scottsdale.

It can be a real pain in the neck to track down interference which would cause the radio frequency to be blocked or interrupted, whichever the case may be. In some cases, it is a matter of shutting off the breaker for each room in the house, one at a time, and trying the remote at each attempt. Once you find the offending room, you can start unplugging devices one at a time, until you find the offending device. Sometimes, it isn't even something in the house, causing it to be even more time consuming. I have seen a few things from cable junctions to electrical junctions, like you would see in the large metal boxes at the curb that have caused the issue. Most of the time, when I come across an interference issue, I recommend going for the frequency change.

Also, to the other post that recommends having the springs checked, sure that is a good idea, if you want a salesman to come into your garage and tell you that your door needs an overhaul, regardless of it's age. I know this because it's my job. A very basic check that anyone can do is to put the door on manual and lift the door by hand. Does it feel heavy? Does it try to fly through the roof? Open the door 1/4 of the way and let go. Does it crash to the floor or start lifting itself? Do the same at the 1/2 way point, and again at the 3/4 mark. The door should stay at any of these positions, maybe rising or falling a couple inches at the most. If the door tries to pull itself all the way open or go crashing toward the floor, call a professional for adjustment or replacement. If you know that your springs are only a few months to a couple years old, in most cases, an adjustment will most likely do just fine.

reply to post by deadlysyn


A rolling code is like a lock. They are not unique. Now if you do it right, there should be enough codes that the odds of your remote opening up another person's garage door is, shall we say, remote, but not impossible. If you go to a large public event with a parking lot, the odds that your remote will open the wrong car are pretty good. It is far worse for physical door locks.

If you didn't see an airplane open a garage door personally, I'd suggest it probably didn't happen. Somebody bumped a remote, the dog bit it, whatever. It takes a sequence of things to be done right to open a remote device. Remote are designed to fail in the direction of not opening.

I've done my share of QRM detection. The problem with garage door remotes is they have very little RF filtering. Remember, the goal for a remote to work is to have a clean signal with the right sequence. You don't want them to be very sensitive, and interference can be a feature since it requires the transmitter to be close to the receiver.

Are those Sommer direct drive DC motor garage door openers any good? Oh, they are on 310MHz. ;-)

I'm willing to bet that smart meters have been installed by the electric company in that area. Garage doors sometimes offer 2 frequencies change it and your problem should go away.


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