Something most folks are not aware of is that household smoke detectors have a 10-year expiration date.  They actually loose their effectiveness over time and need to be replaced.  I have found over the years that most people have never replaced the smoke detector(s) in their house, so it may not even work properly. I regularly find them in homes on inspections with the battery disconnected and even painted over.

A common misconception is pressing the button to make the smoke detector buzz does not actually prove that it works either.  It just proves the battery still has enough power to make it buzz.  What goes bad is the smoke detectors ability to detect or sense smoke.  You would have to perform a smoke test to verify if your smoke detector is truly working or not.  They actually sell canned smoke to complete this test.  However, if you smoke detectors are old it is just better to go ahead and replace them.  Better to be safe than sorry.

Most areas of the country require a minimum of one smoke detector on each floor of your home.  The Commonwealth of Virginia has updated the law to require one in each bedroom and in the adjacent area outside the bedrooms too.  However, not all local city code enforcement offices have adopted the new law just yet, but it will be coming soon.  

The good news is smoke detectors are fairly inexpensive.  Even if you had to buy 5 new smoke detectors, the cost would be minimal.  For the sake of your family, please replace your smoke detectors to ensure yours are in good working order.  It could save your life and the lives of your family!