How old are your smoke detectors?

How old are your smoke detectors?


[lead dropcap="yes"]Everybody knows about one of the expiration dates for home smoke detectors: Every six months– or when we change the clocks in the spring and fall– you should replace the batteries, if they are battery-powered. But did you know that there is another expiration date?[/lead]

I didn’t until recently. I noticed that one of our smoke detectors had been chirping incessantly, even after I’d replaced the batteries and I was wondering if there was something wrong with the detector itself. I started doing some research on the Net and found out that smoke detectors themselves have an expiration date. In fact, you’re supposed to replace them every 8–10 years, according to the US Fire Administration, which is part of FEMA. This makes sense, if you think about how the detector works. The sensors that detect the smoke and/or heat age and become less effective over time.

The other benefit to replacing the smoke detectors is that the technology improves over time. Modern smoke detectors are less prone to false alarms due to cooking and have features like built-in wireless networks, so that for example if a detector on the first floor goes off, all the detectors will sound the alarm, saving you precious minutes.

You can tell how old your smoke detector is because they have a date of manufacture printed on them. If they don’t have a date, it means they are more than 10 years old, from a period when the dates weren’t required, and you should definitely replace them. So I went about checking the dates on the smoke detectors in our house and sure enough four of them had no date, while the rest were about 6 years old.

I decided to replaced the expired detectors with ones that have ionization and photoelectric sensors because each detects slightly different kinds of fire. Better safe than sorry. I settled on the First Alert SA320CN Double Sensor Battery-Powered Smoke and Fire Alarm because they weren’t too expensive and had good reviews on Amazon.

As for the smoke detectors I didn’t replace, I put a timed reminder in my project management and to-do list software of choice, Omnifocus, to alert me in 2017 to buy new smoke detectors and replace those. And then I created repeating reminders to remind in perpetuity.

How much does peace of mind cost? Not very much after all.

Update June 25, 2017: Here's a Lifehacker article on the same topic.

Update November 2018: When it came time to replace the expired smoke detectors in 2017, I chose to switch to the newer Nest Protect, Smoke and Carbon Monoxide smoke detectors. I like the ability to silence them from my phone and to be able to figure out which one has a low battery at 2am by looking at the app and not having to listen for the intermittent chirp that could be coming from anywhere in the house. They're more expensive, but the convenience is worth it to me.

Here are some more smoke detectors that others have found suitable for different use cases than mine. I haven't used them myself so I'm not making any recommendation on them.


Disclosure of Material Connection: Some of the links in the post above are "affiliate links." This means if you click on the link and purchase the item, I will receive an affiliate commission. Regardless, I only recommend products or services I use personally and believe will add value to my readers. I am disclosing this in accordance with the Federal Trade Commission's 16 CFR, Part 255: "Guides Concerning the Use of Endorsements and Testimonials in Advertising."

  • Wow! I feel bad. I’ve lived in this rent house for a year and never checked em. I had 3 total. 1 is 7 years old with no battery! The other 2 are over 10 years old, no dates and dead batteries. Looks like I’ll add a pack of 9vs and 2 new kidda detectors to my shopping list.

  • Wow! seriously, who knew? Time for new detectors ours are 10, 15 and 18yo.
    I change the batteries, I test them regularly…I never realized there was something else required.

  • Thanks. Also fyi co2 detectors have a programed 7 year life both ac and battery. At 7 years they start beeping even after a batery replacement. Keep a nite in this so you don’t go a little crazy at 2 AM after replacing a battery. Been there!

    • Gary – I think that I know what you meant, but they aren’t CO2 detectors, that’s carbon DIoxide. I think that you meant CO detectors, which is Carbon MONoxide. Two very different substances, and if it was just a typing error, I don’t mean to call you out, but people can die from this stuff.

  • How do I get the detector to quit chirping?? I took the battery out & still chirped. Then I removed the whole detector from the ceiling; still chirping. Looks like it’s hard wired so I cut the power according the power box; still chirping . . . Don’t think I can go another night of this chirping . . . HELP!!! Thanks!!

    • Sorry, but I’m not a smoke detector expert. If you’ve removed the battery and cut the wires, then I wonder if there’s a backup battery or if there’s a different smoke detector that’s beeping. You really should get someone out to your house to check it out. If you don’t know who to contact, then call the NON-EMERGENCY number of your local fire department (NOT 911) and ask if they can direct you to someone. Don’t wait. It’s not safe to go without working smoke detectors.

  • Not helpful if I cannot decode the date code and the manufacturer doesn’t have the info on their web site.

    • It shouldn’t be a date code. It should be a clear manufacture date. If it’s a code then it’s likely that your detectors are pre-date the regulation change.

    • I wouldn’t trust it. There are volatile bits that age over time even if never used.

  • We have an obviously old detector. Assembled in Mexico, it bears UL sticker number 33588.
    Model 330L. SP03 is on the back. It connects to house wiring. It sniffs the air with a radio-
    active isotope of some kind. Can someone tell me how old this detector is?

    • Well, as I said in the article, if it doesn’t have a date on the back, then at this point it’s old enough to need to be replaced.

  • The article talks about a manufacture date on back which I assume is what I have. Then people talk about an expiration date. Well which is it?. Of course the unit just has a date which doesnt expalin which it is. The date is 2015 so I am thinking that is about when I bought it. Hopefully not an expiration date like an earlier commenter mentioned. Is the commenter wrong or do some give expiration dates and others unlabled dates that one shouod assume are manufacture dates?

    • The date on the smoke detector is the manufacture date. You calculate the expiration from that so add 8 to 10 years. (The Fire Administration doesn’t give a firm lifespan; you choose how risky you want to be, I guess.)