We had quite the smoke detector ordeal last weekend! My roommate called to say that two of our smoke detectors were beeping - just once every 30 seconds. These are the talking kind so we knew they weren't sensing any smoke or carbon monoxide. After talking to too many people and reading up on the website, I figured out that there was a mechanical malfunction (since we'd already changed the batteries). They were old enough that they needed to be replaced.
I went to Lowe's to pick up two new ones. They were having a special to get $21 off if I got 3. I wasn't going to at first, but really felt like I should. I got them and came home and started unpacking them only to discover that you have to wire them and the directions said to get a qualified electrician, but with a little help from my Dad, I was able to wire them and get them all set.