Liftmaster issue

[five0jo]

When I built a detached garage, I had the Liftmaster 3800 openers installed on the garage doors. Later last year, I replaced the opener on the attached house garage with a regular style Liftmaster. I then started having a problem where when I would use the remote to close the house garage door, a door on the detached garage would go up. Very bad scenario if you didn't check the detached garage every time you would leave the house! As a side note, the detached garage is about 100+ feet from the house. We had the garage door installers come back out and reprogram the opener in the attached garage. But, we continue to have the problem of doors opening on the detached garage when the remote is used for the attached garage door. (I hope this isn't too confusing!)

Anyway - has anyone else experienced such a thing with multiple Liftmaster openers? Is there a "secret" to avoiding this problem?

Thanks!

 

[srmofo]

I would guess the installer didnt really reprogram them. If they have different codes, they will not open other doors. Get out the manual and relearn the remotes/openers.

 

[ScaldedDog]

Yeah, I've got three Liftmasters - 2 3800's and some other one - and have seen exactly what you are seeing. Are yours on the same circuit, by chance, or even the same master switch?

I think the algorithm they use to cycle the codes hash's the time since last "boot" to create the key. When multiple openers are on the same circuit, or the electricity to multiple circuits is switched on at the same time, this occurs randomly. I've gotten in the habit of unplugging two of the openers sequentially after a power cycle, and haven't had the problem in months.

Mark

 

[five0jo]

No - the detached garage is on a separate circuit than the attached garage. The outlets for the 3800s are about 10ft up the wall, so not really easy to unplug those! The installers were supposed to call Liftmaster today, but I haven't heard back. Not a good sign!

But, I feel I should add, I do really like my 3800s and wish I would have spent the additional money put that in the attached garage.

 

[nova65ss]

It sounds like you need to clear them all out and start from scratch. If you hold the purple button down for about 30 seconds it will clear out the stored code. Then you need to reprogram them all by pushing the purple button one time and then push the remote button you are trying to program three times. After the third time the door should travel letting you know it accepted the code.

 

[Gary S]

Yeah, I've got three Liftmasters - 2 3800's and some other one - and have seen exactly what you are seeing. Are yours on the same circuit, by chance, or even the same master switch?

I think the algorithm they use to cycle the codes hash's the time since last "boot" to create the key. When multiple openers are on the same circuit, or the electricity to multiple circuits is switched on at the same time, this occurs randomly. I've gotten in the habit of unplugging two of the openers sequentially after a power cycle, and haven't had the problem in months.

Mark

You likely hit the problem right on the head. Anything that is expected to cycle codes automatically can be expected to malfunction automatically too. Static codes are more reliable than dynamic codes, and this is no different from any other similar situation. I've been in the computer industry since computers were babies, and in networking, static IP is more reliable than dynamic IP. Garage opener codes work the same.