Testing your smoke alarms

What to know

1. Count your alarms. You should have one inside each bedroom, one outside each separate sleeping area, and one on every level, including the basement. Missing one? If you rent, tell your landlord in writing.
2. Press and hold the test button. Hold it on each alarm until it sounds, and do this every month. If it's loud and clear, you're done with that one. If it's weak or silent, see "If it doesn't work."
3. Figure out what powers each alarm. There are three kinds. Some run on a replaceable 9-volt battery. Some have a sealed 10-year lithium battery you can't change. Hardwired alarms connect to your home's wiring and usually have a backup battery.
4. Change batteries once a year. Replace 9-volt batteries, and the backup battery in hardwired alarms, at least once a year. Sealed 10-year alarms don't get new batteries. You replace the whole alarm when the maker says to.
5. Check the date on the back. Twist the alarm off its base and find the manufacture date. Replace any alarm 10 years after that date. If there's no date, assume it's too old.
6. Check for carbon monoxide alarms too. If your home has gas appliances, a fireplace or an attached garage, you need CO alarms. The CDC says to put battery or battery-backup CO detectors near every sleeping area and replace them as the maker says or every 5 years.
7. Set a monthly reminder. Put a repeating reminder on your phone for the 1st of every month. While you're at it, add a reminder to practice your escape plan twice a year, as the Red Cross recommends.