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How Often To Replace Battery In Hard Wired Smoke Detector

man changing battery in smoke detector

How Often To Replace Battery In Hard Wired Smoke Detector

Hard wired smoke detectors may seem to be permanent solutions to fire safety in your home, but they do require some maintenance. Hard wired smoke detectors have back-up batteries which should be tested once a month and replaced once a year.

If the electrical power goes out in your home, it’s critical that even your hard wired smoke detectors have working batteries in case of a fire. Three out of five fire deaths in the home result from nonfunctioning smoke alarms.

Learn More About Smoke Detectors:

How to Replace the Battery In a Hard Wired Smoke Detector

  1. Follow the manufacturer’s instructions for the brand and model of replacement battery for your particular smoke detector.
  2. Always use new batteries; always check the expiration date when purchasing batteries.
  3. Never remove the old battery without replacing it with a new battery.
  4. Make sure you have purchased enough new batteries to replace all of the old ones in all of the smoke detectors in your home. (You should have one smoke detector in each bedroom in your home, one in the hallway outside each bedroom, and one for each level of your home, including the basement. Larger homes may require more smoke detectors. Check your local building codes.)
  5. Test the smoke detector when you replace the battery. Everyone in the household should know what the smoke detector sounds like when it goes off. Everyone in the household should know the escape plan for when the smoke detector goes off. A yearly reminder and drill when replacing the battery could save lives. 

How to Remember to Replace the Battery In a Hard Wired Smoke Detector

The International Association of Fire Chiefs (IAFC) recommends changing your smoke detector batteries each November when you set your clocks back as Daylight Saving Time ends. The IAFC conducts public service announcements each year to remind us to change smoke detector batteries. So, whenever your clocks “fall back,” change your smoke detector battery.

Other options for remembering to change your battery include marking your new calendar at the beginning of each year. You can also set reminders in your smartphone’s calendar app. Marking either your paper or electronic calendar is also a good way to remember to test your smoke detector’s battery each month. Some people replace their battery on January 1st of each year and then test their battery on the first of each month after that.

Whatever you can do to make a regular habit of changing and testing your battery is a good idea!

If You are Renting Your Home or Apartment

Check with your landlord to see when the smoke detector was installed. If the landlord is uncertain, check the unit itself for date of manufacture. All smoke detectors, including hard wired units, should be replaced every ten years. If you’re unsure when the battery was last replaced, replace it immediately and then once yearly after that. And don’t forget to test the battery every month!

How Long Do Batteries Last In a Smoke Detector?

Smoke Detector Facts

  • Three out of five home fire deaths result from fires in properties without working smoke alarms
  • More than one-third (38 percent) of home fire deaths result from fires in which no smoke alarms are present.
  • The risk of dying in a home fire is cut in half in homes with working smoke alarms.


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