Test and replace smoke and CO alarms
Seven in ten homes we inspect have a smoke alarm coverage problem, and most of the time the fix is a new unit rather than a new battery. The sensor inside loses sensitivity after about ten years even when the test button still beeps.
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- Count them. You want one in every bedroom, one in the hall outside each sleeping area, and at least one on every level including the basement. A CO alarm belongs near sleeping areas and near any fuel-burning appliance or attached garage.
- Twist each one off and read the back. The manufacture date is printed there. Ten years or older gets replaced. No date means it's old enough.
- Press and hold the test button. A loud alarm within a few seconds is a pass. Silence, a weak chirp, or a delay is a fail.
- Replace batteries in the ones you keep. Once a year, on a date you'll remember. Alarms with sealed ten-year batteries skip this until the unit itself expires.
- Install replacements. Combination smoke and CO units cost little more than smoke-only. Hardwired homes take a hardwired replacement with the same connector; battery-only homes take battery units. Mount on the ceiling or high on the wall, away from vents and corners.
- Vacuum them. Dust in the sensor chamber causes both false alarms and missed ones. A quick pass with the brush attachment once a year.
When it's past the do-it-yourself line
If the hardwired alarms don't all sound together when one is tested, or wiring looks damaged, an electrician should look. Otherwise this is one of the few life-safety items that is genuinely a homeowner job.
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