When Should Smoke Detectors Be Replaced?

Replace at ten years

NFPA and CPSC guidance says to replace smoke alarms when they are ten years old. The date is usually printed on the back, which may require safely removing the unit from its mounting ring.

Replace sooner when necessary

A unit that fails its test, is damaged, has been painted, repeatedly faults after proper maintenance or is subject to a manufacturer recall should not be treated as good merely because it is under ten years old. Follow the manufacturer’s instructions.

Yellowing is a cue, not a date

Discoloration can be a useful visual clue that an alarm is old, but it is not a calibrated expiration test. Read the label and assess the condition of the entire set.

Record the new date

When replacements are installed, record the installation and replace-by dates in a household file. Keeping the alarms on one understandable schedule makes the next maintenance cycle far easier.

Safety references

Primary sources used for this page:

• NFPA smoke-alarm safety guidance
• U.S. CPSC fire-safety guidance

Manufacturer instructions and current local requirements control. For an emergency, call 911.