Most of us know to swap out smoke alarm batteries. Far fewer people know the alarm itself has an expiration date.
A smoke alarm is a sensor, and sensors wear out. Dust builds up inside. Parts age. An alarm that has been up on the ceiling for a long time may still beep when you press the test button. That doesn’t mean it’ll pick up smoke as fast as it should.
Finding the date
Take the alarm down. Most twist right off the base. Somewhere on the back there’s a date, and it’s the date the alarm was made, not the date someone put it up.
That difference matters more than you’d think. An alarm that sat in a box in the garage for two years before anyone installed it has already burned two years of its life.
No date, or you can’t read it? Treat it as overdue. Some people write the date on a strip of tape inside the base so they don’t have to go hunting next time.
What the date means
Count forward from it. Smoke alarms are generally meant to be replaced 10 years after they were made. Carbon monoxide alarms and combination smoke and CO units often have a shorter life, so check the label or the manual.
Some newer alarms have sealed batteries that last as long as the alarm does. Many chirp at the end of their life, and a fresh battery won’t stop that chirp. The fix is a new alarm.
Why the first minutes count
Fires grow fast. An alarm that goes off in the first minute gives everyone time to get out, and it gives the fire department a shot at stopping the fire while it’s still in one room.
That second part matters long after everyone is safe. Restoration firms like the Kiser Construction team deal with the aftermath either way. But a fire that gets caught early usually leaves a lot less to clean and rebuild than one that burned for a while before anybody knew.
An alarm is cheap. What it buys you is minutes, and those minutes are worth more than anything else in the house.
Where alarms belong
While the ladder’s out, check where they are. You want one in every bedroom, one outside each sleeping area and one on every level of the house, basement included. Test them once a month.
Minnesota adds a rule of its own. State law requires a working carbon monoxide alarm within ten feet of every bedroom, in single-family homes and apartments alike. If your CO alarms are getting old too, replace them at the same time.
Hardwired alarms that are linked together all go off at once, so a fire in the basement wakes up the people upstairs. If you’re replacing hardwired units, have an electrician confirm the new ones work with the old wiring.
What a major alarm maker recommends
Smoke alarm maker Kidde spells out when to replace smoke alarms. Citing the National Fire Protection Association, Kidde recommends replacing smoke and heat alarms every ten years, and carbon monoxide and combination alarms every seven to ten years depending on the model. If you aren’t sure how old an alarm is, Kidde says to check the back for the manufacture date and to replace it if you’re in doubt.
It’s maybe a 20-minute job with a step stool. Pull each one down, read the date, and replace anything 10 years old or with no date at all. Few home projects that easy can actually save a life.