Combination smoke and CO alarm
Covers both fire and carbon monoxide detection in one unit — useful near attached garages and fuel-burning appliances.
Compare on AmazonSmoke Alarm Checklist for New Homeowners
A home inspection confirms alarms are present and test successfully at that moment — it doesn't necessarily tell you their age or whether coverage matches current guidance. Do your own walkthrough in the first week.
Your first-week walkthrough
- Locate every smoke and CO alarm in the home and mark them on a simple floor-plan sketch.
- Check each alarm's manufacture date (usually printed on the back) — previous owners rarely leave this information behind.
- Test every alarm yourself, even if the inspection report says they passed.
- Compare your alarm count against the recommended minimum for your layout: one inside every bedroom, one outside each sleeping area, and one per level including the basement.
- Note whether existing alarms are interconnected (wired or wireless) — if only some are, a fire in one part of the house may not sound alarms elsewhere.
- Check for CO alarm coverage if the home has a gas furnace, gas water heater, gas range, attached garage, or a fireplace/wood stove.
Why "it passed inspection" isn't the whole picture
A general home inspector typically confirms alarms are present and sound when tested — a useful baseline, but not the same as checking each unit's age against the 10-year replacement rule, or confirming your specific bedroom/level layout has full coverage under current guidance. Previous owners also don't always leave documentation of when alarms were installed.
Run the numbers on your new home
Enter your home's layout and each alarm's manufacture date to get a clear missing-count and expired-count for your specific house.
Tools and supplies to consider
These links go to an Amazon search so you can compare current options and prices.
10-year sealed battery smoke alarm
A sealed 10-year battery alarm removes the annual battery-swap chore for the life of the unit.
Compare on AmazonInterconnected wireless smoke alarm kit
When one alarm sounds, they all sound — useful in larger homes or homes with long hallways.
Compare on AmazonStandalone carbon monoxide alarm
A dedicated CO alarm for rooms near fuel-burning appliances or an attached garage.
Compare on Amazon9V alkaline batteries (multipack)
Keeps battery-powered alarms working between the annual replacement reminder.
Compare on AmazonLightweight step ladder
A stable way to reach ceiling-mounted alarms for testing and battery changes.
Compare on AmazonFrequently asked questions
The inspector said the alarms are fine — is that enough?
It confirms they were present and sounded during the test. It doesn't necessarily confirm their manufacture date is within 10 years or that your layout has full coverage under current guidance.
Should I just replace every alarm when I move in?
It's a reasonable, low-cost way to start with a known baseline, especially if you can't determine the existing units' ages.
What if the previous owner left no documentation?
Check each unit's manufacture date yourself — it's usually printed on the back or side of the alarm regardless of what paperwork was or wasn't left behind.
Related on HomeRuleCheck: the smoke & CO safety overview, when smoke alarms expire (the 10-year rule), how to dispose of an old smoke detector, and the smoke alarm coverage & expiration checker.