Replace most smoke alarms every 10 years. Replace one sooner if it fails testing, is damaged, has reached the replace by date, or the manufacturer instructions specify a shorter life.
Quick schedule
- Monthly: test smoke alarms.
- As needed: replace batteries according to the alarm type.
- Every 10 years: replace most full smoke alarm units.
- Sooner: failed test, damage, missing date, or end of life chirp.
Why smoke alarms expire
Smoke alarm sensors don't last forever. Dust, age, and component wear can reduce reliability over time. A smoke alarm can look fine and still be past its replacement window.
How to check the age
- Take the alarm down from its mounting plate.
- Look for a manufacture date or replace by date on the back.
- If there is only a manufacture date, add 10 years unless the label says otherwise.
- Replace the alarm if the date is missing, unreadable, or expired.
Battery replacement is different
Replacing batteries keeps a working alarm powered. It doesn't reset the age of the smoke sensor. A 12 year old alarm with a new battery is still old.
Hardwired alarms expire too
Hardwired smoke alarms are connected to household power and often have backup batteries. They still contain sensors that age. If you aren't comfortable replacing a hardwired alarm, hire an electrician or qualified pro.
Replace with the right type
Follow local code and manufacturer guidance. Some homes require interconnected alarms, combination smoke and carbon monoxide alarms, or specific placement. Don't downgrade a required system because a cheaper alarm fits the bracket.
Good maintenance rhythm
- Monthly: test each alarm.
- Yearly: check manufacture dates while cleaning or testing.
- Every 10 years: replace most smoke alarms.
- Sooner: failed test, damage, end of life warning, or unclear age.