This is one of those things everyone assumes is handled.
Smoke alarms are there. CO detector’s on the wall. Maybe one chirps every now and then when the battery’s dying.
Looks fine. Feels fine.
And then you actually test how the system works — or doesn’t.
The Big Shift Most Homeowners Missed
The big change isn’t having detectors anymore. It’s how they’re expected to work together.
Modern safety standards are pushing hard toward interconnected alarms. When one goes off, they all go off.
Why? Because fires don’t stay in one room, and people don’t sleep with doors open anymore.
What “Interconnected” Really Means
Interconnected alarms communicate with each other, either by:
- Hard wiring
- Wireless signal
- Combination systems
So if smoke starts in the basement at 2 a.m., the alarm outside the bedroom upstairs goes off too.
That matters. A lot.
A Real Inspection That Changed a Buyer’s Mind
I inspected a home near Jackson where smoke detectors were present in every bedroom. Seller was proud of that.
But none of them were interconnected.
When we talked it through, the buyer realized something uncomfortable: if a fire started in the garage or basement at night, the alarm closest to them might not sound loudly enough — or at all — where they were sleeping.
That’s not a technical failure. That’s a design gap.
CO Detectors Get Even More Misunderstood
Carbon monoxide is sneaky. No smell. No color. No warning.
I still see CO detectors:
- Installed too low
- Installed too high
- Installed too far from sleeping areas
- Installed only near the furnace
- Installed in kitchens (bad idea)
They’re present — just not effective.
Why Placement Matters More Than Quantity
You can have ten alarms and still be unsafe.
Smoke detectors need to be:
- In sleeping areas
- Outside sleeping areas
- On each level of the home
CO detectors need to be:
- Near sleeping areas
- At proper height depending on manufacturer
- Away from fuel-burning appliances
Random placement doesn’t equal protection.
The Interconnectivity Gap in Older Homes
Older homes weren’t wired with this in mind.
I’ve reviewed inspection reports from one of our inspectors near Bolivar where homes had functional alarms — but no practical way for them to communicate without upgrading.
That doesn’t mean the house is unsafe. It means expectations have changed.
The “They All Went Off Once” Myth
I hear this a lot:
“Oh yeah, one went off and they all went off.”
Sometimes that’s true.
Other times, it was just sound carrying through the house.
That’s why actual testing matters. Not assumptions.
What I Look For During an Inspection
I don’t certify alarms — but I do evaluate them.
I look at:
- Presence and placement
- Type (smoke vs. CO vs. combo)
- Power source
- Age of units
- Interconnection where visible
- Gaps near sleeping areas
And I document limitations clearly. Detectors don’t get a free pass just because they exist.
What Buyers Should Understand
Alarm upgrades are usually:
- Relatively inexpensive
- Straightforward
- High-impact for safety
They’re one of the few improvements that directly buy time when things go wrong.
The Inspector’s Bottom Line
Smoke and CO alarms aren’t about checking a box. They’re about waking you up when your instincts can’t.
Interconnectivity isn’t a luxury feature — it’s recognition of how fires and gas actually behave.
If one alarm goes off and the rest stay quiet, the system isn’t finished yet.
