A photo of a first generation Nest Protect smoke alarm.
Nest

Smart smoke detectors are quite a bit more expensive than their “dumb” counterparts, so it’s only natural for people to consider their lifespan and replacement costs. Here’s what you need to know about the lifespan of smoke alarms.

It’s a Trick Question: All Smoke Alarms Expire

The title of this article “Do Smart Smoke Alarms Expire?” is a bit of a trick question. All smoke alarms “expire” in that they become less accurate over time and need to be replaced.

The materials in the smoke alarm sensor degrade, particulate matter accumulates over time on the sensors, and slow corrosion of the contacts and electrical components inside the alarm can lead to false alarms (or no alarm at all).

So that yellowed old smoke alarm might still sound an alarm if you were to light a match directly under it, but its capacity to detect smoke particulate from a fire across the room is likely diminished or non-existent.

Worse yet, the phantom chirps and false alarms that plague old smoke alarms often lead people to pull the battery out—and then they forget to replace the battery or install a new smoke alarm. According to the National Fire Protection Association (NFPA), in nearly half the instances where smoke alarms were present but failed to sound the alarm, the cause of the failure was a missing battery.

Home fires spread quickly and every second counts when it comes to getting out safely and containing the fire. That’s exactly why both manufacturers and the NFPA recommend you replace all smoke alarms in your home every 10 years (or sooner if recommended by the manufacturer.)

Smart Smoke Alarms Force Your Hand

Despite the strong stance on the matter from smoke alarm manufacturers and the NFPA, many people are surprised to learn smoke alarms expire.

The primary reason for this surprise is that, unless you read the fine print when you purchase the smoke alarm or you happen to enjoy reading NFPA safety briefings, it’s easy to overlook. Even if you do both of those things, it’s all too easy to forget and not replace your smoke alarm.

Unlike dumb alarms that typically have no idea when they were manufactured and rely on you to swap them out, smart alarms have the ability to keep track of time and alert you when they are expired. This gives the smoke alarm the ability to not just alert you of the expiration date but even enforce it.

One of the most notable examples of this is the Nest Protect smart smoke and carbon monoxide alarm. While there are certainly other smart smoke alarms on the market, the Nest Protect is very popular. When it reaches its expiration date it lets you know rather vocally.

Within two weeks of expiration, the indicator light turns yellow, and it announces “Nest Protect has expired. Replace it now.” Also, upon the official expiration date, the Protect disables itself. Ignore all that, and it will resort to chirping incessantly at you with the last of its battery life.

The expiration date label on a Nest Protect smart smoke alarm.
Come January 2032, I’ll be replacing them all again. Jason Fitzpatrick / How-To Geek

As annoying as that might be, it does force you to pay attention to the expiration date and replace your smoke alarm at an appropriate time.

I recently spent an hour replacing all my smoke alarms thanks to the Protect’s vocal insistence. If it’s been a decade or two since you replaced your smoke alarms now would be a great time to pick up a few and do the same.

And if you’d like smarten-up your traditional smoke alarms so you can get alarm notifications when you’re away from home—you know, without the expense of putting a pricey smart smoke alarm in every room—you can always configure your smart speakers to listen for the alarm.

Profile Photo for Jason Fitzpatrick Jason Fitzpatrick
Jason Fitzpatrick is the Senior Smart Home Editor at How-To Geek. He has over a decade of experience in publishing and has authored thousands of articles at How-To Geek, Review Geek, LifeSavvy, and Lifehacker. Jason served as Lifehacker's Weekend Editor before he joined How-To Geek.
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