fireSmoke detectors are used to protect your family from smoke and fires in your home. These two things can catch you off guard while you’re in a deep sleep. Fires and smoke inhalation injured and kill many people each year. By having smoke detectors in and around bedrooms and hallways, these tragedies can be avoided.
Hardwired smoke detectors are wired so that if one detector warns of smoke or fire, the others also go off. This way, all areas of the home are warned. The other nice feature is battery backup. The detector runs on 125-volt power until the power goes out. Then the battery kicks in and keeps right on protecting you!

If your home was built in the last 20 years, you probably have hardwired smoke alarms. If only the alarm that you test sounds, then you do not have an interconnected system.