Test smoke and CO detectors
Twice a year · typically March and November
Why it matters
Detectors are the one system in your house where "it looks fine" means nothing — the sensor inside degrades on its own schedule regardless of how clean the outside is. Smoke detectors expire at 10 years, CO detectors at 5–10 depending on the model, and the manufacture date is printed on the back of every unit.
March and November are the rhythm: the old change-your-clocks habit, minus the clocks.
What skipping it costs
$0–$25,000
Three out of five home-fire deaths happen in homes with no working alarms. The dollar column can't carry this one — but for what it's worth, the average insured fire claim runs well past $25,000, and the detector that catches it early is thirty bucks and two test presses a year.
Two ways to get it done
Do it yourself
You'll need: A broom handle or step stool to reach the test button, 9V or AA batteries per your models (skip if yours are sealed 10-year units).
- Press and hold the test button on every unit until it screams. All of them — the hallway one you always do and the basement one you always forget.
- If any unit is interconnected, confirm the others sound too.
- Swap batteries in any unit that takes them (skip sealed 10-year units).
- Flip each unit and read the manufacture date. Smoke over 10 years old or CO over its stated life gets replaced this week, not "sometime" — a $25–$40 errand.
- Vacuum the vents on each unit while you're up there; dust is the main cause of nuisance false alarms, and false alarms are why people pull batteries. Pulled batteries are how the statistic above happens.
Hire it out
$350–$650National fair range — local labor moves this number.
There's nothing to hire for testing — it's a button. Where a pro earns their fee is upgrading old, non-interconnected units: an electrician wiring interconnected combination detectors through the house runs $350–$650, and it's genuinely worth it in an older home, because interconnection (the garage alarm waking you in the bedroom) is the feature that saves lives at 3 a.m. What you don't need: monthly monitoring subscriptions sold on fear, or a whole-panel "code compliance" upsell that started with a detector question.
Ask the tech
- Are these interconnected — when one sounds, do they all sound?
- Are you installing sealed 10-year units or ones I'll be feeding batteries?
- Combination smoke/CO on every level, or CO only near the bedrooms?
Red flags you're being upsold
- A 'code violation' pitch to rewire the whole house that started as a detector call.
- Monitored-alarm subscription hard sells — a $30 detector wakes you up exactly as well without the monthly fee.
The call
DIY, twice a year, no exceptions — and put replacement dates on your calendar, because every detector expires whether it looks fine or not.