Q: Why is my garage door opening by itself?
A: When a door opens by itself it can be time consuming to diagnose what is activating opener randomly. It could be an internal short inside opener or an external short in wiring. Or the other reason is frequency interference. (Frequency: The radio signal that is sent to opener to activate and open door from a distance.)
Sometimes a neighbor has a remote on same frequency as yours, or the wall button has a short in it, or there is a wall button wire that may be touching each other especially if all opener wiring is pre run behind walls when home was built. residents living near commercial airports can have frequency issues from commercial jets. also some home wireless internet signals can affect frequency with garage door opener. Home warranty companies and opener manufactures do not cover frequency issues. Older openers can also have a wall button wire that has come loose or broken off and is touching opposite wire and activating opener.
If you have a neighbor with the same frequency as your opener it is most likely older equipment and probably be replaced with up to date opener. A wall button that is 10 to 15 years old can deteriorate and short out and activate opener you will need to replace button. Wiring can also short out from being stapled to wall and ceiling. over time the staples can scratch off wire insulation and activate opener. Homes located very close to commercial airports can see frequency issues with there opener, usually models manufactured before year 2000.
I have had openers open by itself because the homeowner replaced her remotes and left the old one she thought wasn’t working in a junk drawer and forgot about it for years and was causing door to open randomly. Working for 3 years for 2 home warranty companies that cover repairs on garage door openers. I have seen a customer install some hi tech wireless internet equipment and all the sudden his door would open randomly. Frequency interference not covered by home warranty policies. Any kind of renovations in or near garage can damage wiring that controls opener especially wiring ran behind walls or attic and crawl spaces above garage ceiling.
If you are experiencing a door opening up by itself and can’t figure out why than unplug opener until you can get a technician to your home. This will give peace of mind when gone during day or asleep at night.