The furnace kicks on for the first cold night. Somebody lights the fireplace. The kids are home more, the oven is running more, and the house is sealed up tight until spring.
That makes right now the best time of year to do one boring, important job: check every smoke alarm and carbon monoxide (CO) alarm in the house. It takes about 30 minutes, a step stool, and a flashlight.
Here’s the routine.
Why this matters more than it feels like it does
A smoke alarm that’s dead, missing a battery, or past its life is the same as having no alarm at all. The U.S. Fire Administration says it plainly: a smoke alarm only works when it’s properly installed and regularly tested.
Carbon monoxide is worse in one way. You can’t see it or smell it. The only way to know it’s in your house is an alarm. It comes from anything that burns fuel: a gas furnace, gas water heater, gas stove, a fireplace, or a car running in an attached garage. Cold months are when those things run the most.
Step 1: Walk the house and count (5 minutes)
Grab a notepad or open a note on your phone. Walk every level, including the basement, and write down every alarm you find and where it is.
Then compare against where the safety agencies say alarms should be:
Smoke alarms (NFPA and the U.S. Fire Administration):
- Inside every bedroom.
- Outside each sleeping area, like the hallway outside the bedrooms.
- On every level of the home, including the basement.
- On the ceiling or high on the wall.
CO alarms:
- Outside each separate sleeping area.
- On every level of the home.
- Not right next to the furnace, fireplace, or other fuel-burning appliance. The B.C. government suggests keeping them at least 15 feet from fuel-burning appliances, and away from windows, vents, and bathrooms.
- If you only have one, put it in the main bedroom or the hallway outside the bedrooms.
Circle any spot on your list that’s missing an alarm. That’s your shopping list.
Step 2: Press every test button (10 minutes)
Climb up and hold the test button on every alarm until it sounds. Some CO alarms take a while: the City of Vancouver notes it can take up to 20 seconds, so hold it down long enough before you decide it’s dead.
Make it a kid job. Have one kid stand in their bedroom with the door closed while you test the hallway alarm. Can they hear it? If an alarm in one part of the house can’t be heard in a bedroom, that bedroom needs its own alarm, or you need alarms that are interconnected.
Interconnected means when one alarm sounds, they all sound. NFPA calls this the best protection. Many newer homes have hardwired interconnected alarms already. If yours doesn’t, wireless interconnected models exist that link without running new wires.
Step 3: Check the dates (5 minutes)
This is the step most people skip. Every alarm has a manufacture date printed on the back. Take each one down (they usually twist off the base) and look.
- Smoke alarms: replace the whole unit 10 years from the manufacture date. Both NFPA and the U.S. Fire Administration say this.
- CO alarms: replace them every 5 to 10 years, or whatever the manufacturer says. Many CO alarms will start chirping or show an end-of-life signal when they’re done. Check the label on yours.
If there’s no date at all, or the date is faded and you can’t read it, assume it’s old and replace it.
Write the replacement year on the alarm with a marker so the next check takes two seconds.
Step 4: Batteries (5 minutes)
What you do depends on the type of alarm:
| Alarm type | What to do |
|---|---|
| Replaceable battery (like a 9-volt) | Test monthly. Change the battery at least once a year. |
| Sealed 10-year battery | Test monthly. You can’t change the battery; replace the whole alarm when it reaches end of life. |
| Hardwired | Test monthly. Change the backup battery at least once a year. |
A good habit: change replaceable batteries on the same weekend every fall so you never have to wonder when you last did it.
Never pull the battery to stop a cooking false alarm. Open a window, wave a towel at it, and press the hush button. If the kitchen alarm goes off every time you sear a steak, the alarm may be too close to the stove. Moving it a few feet farther away is a better fix than a missing battery.
Step 5: Clean and clear (5 minutes)
Dust and cobwebs can mess with an alarm’s sensor. The B.C. government suggests vacuuming CO alarms with a soft-brush attachment or wiping them with a dry cloth. Do the same for your smoke alarms while you’re up there.
Then step outside and take a look at the vents for your furnace, dryer, and water heater. Make sure nothing is blocking them: leaves now, and snow later in the winter.
The rules where you live
Rules vary a lot by location, so check yours. A few examples:
- In B.C., smoke alarms are required in every home under the BC Fire Code, and homeowners are responsible for installing and maintaining them. CO alarms are required in new homes with a fuel-burning appliance, fireplace, or attached garage, and the province recommends them in any home that has one of those.
- In the City of Vancouver, the fire bylaw goes further: every home, new or old, with an attached garage or a fuel-fired appliance (furnace, water heater, stove, or fireplace) must have CO alarms.
- In the U.S., smoke and CO alarm rules are set by states and cities. Your local fire department’s non-emergency line can tell you what applies. Some U.S. fire departments will even install battery smoke alarms for free.
Whatever the law says, the safety advice is the same: if your home burns any fuel or has an attached garage, get a CO alarm.
Bonus: the 2-minute fire drill
Alarms only help if everyone knows what to do when they go off. After the check, gather the kids for two minutes:
- Play the sound. Press the test button so the kids know what the smoke alarm sounds like, and that it means get out.
- Two ways out. Walk each kid’s room and point out two ways out: the door and a window.
- Pick a meeting spot outside, like the mailbox or a neighbor’s driveway.
- Know the CO rule. If the CO alarm sounds, everyone goes outside right away, then you call 911 from outside.
Little kids may sleep right through an alarm. Test it one night and see. If they don’t wake up, the plan needs to include an adult going to get them.
Your 30-minute fall checklist
| Time | Do this |
|---|---|
| 5 min | Walk every level. List each alarm and circle the gaps. |
| 10 min | Test every alarm. Check you can hear it from each bedroom. |
| 5 min | Check manufacture dates. Mark the replacement year on each one. |
| 5 min | Change replaceable batteries and backup batteries. |
| 5 min | Dust the alarms and check outside vents are clear. |
| Bonus | Two-minute fire drill with the kids. |
What to buy if you found gaps
Keep it simple:
- Combination smoke and CO alarms cover both jobs in one unit, which is handy for hallways outside bedrooms.
- Sealed 10-year battery alarms mean no more yearly battery swaps and no 3 a.m. low-battery chirp.
- Interconnected alarms if your current ones aren’t linked and the bedrooms are spread out.
- A sturdy step stool that lives in the same closet as the spare batteries.
Look for alarms certified for your country (in Canada, look for a ULC mark; in the U.S., a UL listing).
Your move this weekend
- Do the walk-through and write the list.
- Test, date, and battery-check every alarm.
- Run the two-minute drill with the kids at dinner.
It’s not glamorous. Nobody will thank you for it. But on the one night it matters, the alarm will go off and everyone will know exactly what to do. That’s the job.
This is general safety information. Always follow your alarm manufacturer’s instructions and your local fire code. For hardwired alarms, use a qualified electrician.