if it opens when power goes out it has a battery backup. if it closes via the remote, teh sensors are fine. some are both green, some are different colors.

what is the model of the opener?

Just to confirm, do you have an "Overhead Door Company" BRAND machine? Or an "Overhead Door" garage door? Or are you perhaps using that term loosely?

May seem like redundant questions, but many people assume the brand of door and the machine are one of the same when most often, they are not. And the term "overhead" is commonly used to describe the position of the opener/door when in fact the brand of equipment could be Liftmaster, Craftsman, Genie, Clopay, Wayne Dalton, Holmes, etc.

I am not aware of any Overhead Door Company brand machines that are equipped with an optional battery backup system.

Just to confirm, are you saying that when the power goes out (either because of a failure or you manually shut the power off to the house) the door automatically opens all by itself? If so, what happens when you unplug the machine from the ceiling?