- Smoke alarms over ten years old, regardless of how they operate, should be replaced.
- If they are hard wired into your home's electrical system, and are less then 10 years old, all you need to do is replace the back up battery. A good old fashioned 9 volt back up battery is fine for these hard wired alarms.
- If you have a battery operated smoke alarm, check to see what kind it is. Somewhere on the alarm it should say if it is ionization or photo electric. If the smoke alarm is of the ionization type, make sure it's less than ten years old, has a long life battery in it, and then test it to make sure it works. If the smoke alarm says that it's a photo electric type, than it should already have a long life lithium power cell, as a nine volt alkaline doesn't have enough energy to power a photo electric alarm for very long. Test your photo electric alarm and call it good.
- It's also a good idea to dust your smoke alarm out, using a can of computer keyboard cleaner or a vacuum, gently clean the device to remove any dust, cob webs, or other debris that could keep your smoke alarm from working properly.