You should have at least one smoke detector in each bedroom, in the hallway outside each bedroom and at the top of all stairways. Smoke rises, so the best place to install a detector is on the ceiling or high on an inside wall approximately 6 to 8 inches below the ceiling. However, do not install a smoke detector within three feet of any device that might blow the smoke away.
Anytime your smoke detector goes off, it's important to pay attention. If it's sounding its loud alarm it's because it senses the presence of smoke; check your home thoroughly. If you smell smoke and are unable to locate a fire, call 911 and we'll send an engine to make sure that a fire isn't smoldering in a hidden area and it won't cost anything. If you don't smell smoke, the detector may be reacting to the presence of dust, steam, or a small insect or spider. Dust and bugs can be removed by a vacuum cleaner. If steam from a nearby shower is affecting your smoke detector regularly, move the detector to a different spot.
If the detector is just chirping, thumping, or buzzing, it probably means that the battery is low. Replace the battery as soon as possible. Without a working battery, a smoke detector can't do its job and the risk of dying in a fire increases greatly.