Combination smoke and CO alarm
Covers both fire and carbon monoxide detection in one unit — useful near attached garages and fuel-burning appliances.
Compare on AmazonSmoke Alarm Expiration Checker
Smoke alarms expire 10 years from their manufacture date — not the day you installed them. If you can't find a manufacture date, the safest move is to replace the alarm.
Why alarms expire at all
A smoke alarm's sensor gradually loses sensitivity over time, along with the rest of its electronics. After about a decade, manufacturers and fire-safety authorities no longer consider the unit reliable enough to trust — even if it still beeps when you press the test button. A working test beep confirms the battery and horn work; it does not confirm the smoke sensor itself is still accurate.
How to find your alarm's manufacture date
- Look on the back or side of the unit — most manufacturers print or stamp a manufacture date directly on the case.
- Some brands use a date code instead of a plain date; check the manufacturer's website with your model number if the code isn't self-explanatory.
- If you genuinely cannot find or determine a date, the safest assumption is to replace the alarm rather than guess it's still within range.
Check every alarm in your home at once
Enter each alarm's manufacture date into our checker and it will flag anything expired or due soon, alongside whether your home has enough alarms in the first place.
Replacement alarms and supplies
These links go to an Amazon search so you can compare current options and prices.
10-year sealed battery smoke alarm
A sealed 10-year battery alarm removes the annual battery-swap chore for the life of the unit.
Compare on AmazonInterconnected wireless smoke alarm kit
When one alarm sounds, they all sound — useful in larger homes or homes with long hallways.
Compare on AmazonStandalone carbon monoxide alarm
A dedicated CO alarm for rooms near fuel-burning appliances or an attached garage.
Compare on AmazonFrequently asked questions
Does it matter if the alarm still beeps when tested?
No — a working test beep confirms the battery and horn function, not that the smoke sensor itself hasn't degraded.
What if I can't find a manufacture date?
If the date truly can't be determined, replace the alarm — it's the safer default than assuming it's still within its 10-year window.
Do hardwired alarms expire on the same schedule?
Yes. The 10-year rule is about the sensor and electronics, not the power source.
Is the expiration date the same as the battery's life?
No — a 10-year sealed battery lasts as long as the alarm's rated life, but a replaceable 9V battery needs changing far more often, typically once a year.
Related on HomeRuleCheck: the smoke & CO safety overview, where to place carbon monoxide alarms, and how to dispose of an old smoke detector.