A reader recently sent in the following question:
"Do you have any idea why our garage door opener would suddenly open and close by itself? Ours started doing that two days ago. It will do it over and over and sometimes it only goes part of the way and stop. Sometimes you can push the button and it will stop it and sometimes and will just keep going up and down until we unplug it. My husband tried cleaning it out and changing the codes and several things. He usually can figure out how to fix something but this one has left us puzzled. Any ideas?"
A garage door opener with a mind of its own can be a real pain. It can also be dangerous and an invitation to uninvited guests.
Check the Garage Door Wiring
My first suggestion would be to change the code in case of the very rare possibility that a neighbor's remote is somehow controlling your door. But the reader had already tried that. My next thought would be to check for a short in the wiring between the opener motor unit and the wall button in the garage. Also, check the wiring between each of the safety sensor eyes at the sides of the door and the motor unit. These are low-voltage wires so you don't have to worry about shutting off the power to check them. Look for damaged insulation, bare strands of wire, or even a nail or staple piercing the wire.
If the wires look good, turn your attention to the buttons, on both the wall and the remote. If they are old, they can start sticking. You also might find wiring issues inside the button housing, perhaps causing an electrical short.
Both parts should be replaceable.
Check the Circuitry of a Garage Door Opening by Itself
Since the door is not only going up by itself but also down by itself, your problem is not likely to be solved by the usual remedies. Doors that go down on command but then reverse themselves automatically usually have a problem with the safety sensor eyes, or the door is binding, or there's something like snow or ice preventing it from closing all the way, triggering the auto-reverse function.
This is why I thought you should check the wiring and wire connections, which seem to suggest an electrical problem. Unfortunately, that also might point to the opener's logic board or circuitry.
I have heard tales of malfunctioning circuit boards that cause the doors to open by themselves and the lights to flash. I can't suggest how to repair it — it's possibly just a simple solder repair — but it might give you some idea of where to look. A veteran garage door repair person might be able to help you out. Just be aware that a service call may cost almost as much as a new opener.
Check Everything Else
Beyond that, here are two pieces of advice:
1. Do a thorough troubleshooting and maintenance check. See Troubleshooting the Most Common Garage Door Opener Problems and Simple Garage Door Maintenance Tips.
2. When all else fails, a replacement would almost certainly take care of the problem, especially if you have an old unit. See 5 Reasons to Replace Your Garage Door Opener.
Installing a new opener is a very doable project for any moderately handy person.
Given that the problems with your opener pose real safety and security risks, a new opener makes a lot of sense if you can't stop its mysterious behavior soon.