You hit the button and the opener groans a little longer than it used to before the door finally lifts. Or maybe you've noticed the door creeping back down an inch or two after you stop it halfway, like it's trying to close on its own. Most homeowners assume this means the opener is wearing out and start pricing a replacement. Often, though, the opener is fine. It's the door's spring balance that's off, and the opener has just been quietly compensating for it, probably for months.