You may have your schedule enabled via the iOS or Android App. When the schedule is enabled, Opal will check to see if it should be on or off once every hour. If you manually turn your Opal off, but it is scheduled to be on, it will turn on the next time it checks the schedule. This will usually occur at the top of the hour. To fix this issue, go to your app and disable the schedule. Another way to disable the schedule is to unplug your Opal, wait a few seconds, then plug it back in.