Malfunctioning circuit boards, a power surge or a thunderstorm are potential causes of a garage door opening by itself. In rare cases, a neighbor may accidentally open a homeowner's garage door, especially if the door has been operating for more than 20 years already.
The transmitters of very old garage door openers tend to have fewer codes compared to newer models, making it possible for neighbors' remotes to open the doors unintentionally. Newer garage doors are less likely to open with the use of other remotes, as they transmit varying codes that continuously change with countless combinations.
If a homeowner lives close to a military base, there is a possibility that electrical equipment running on the same frequency as the garage door opener triggers the door to open. Additionally, a power surge or thunderstorm can affect the transmitter's electrical mechanism, causing a garage door opener to operate randomly. This requires service repair or replacement of the opener.
To troubleshoot an improperly functioning garage door, the owner may try changing the code by removing the remote's cover, searching for the code wheel and selecting a new code. The next step is to access the opener and modify the code accordingly. It helps to read the manufacturer's manual if it's difficult to locate the code wheel in the garage door opener.