When an alarm goes off in your home, you want to know exactly what it’s telling you. But many homeowners aren’t sure which alarm is which, or if they even have both. That small gap in understanding can mean your home isn’t as protected as you think.
At Integra Electrical, we’ve walked into plenty of homes with smoke detectors in the wrong places, carbon monoxide detectors missing, or units so old they may not work at all. Each device plays its role in keeping your family safe, and knowing the difference makes it easier to stay prepared.
By the end of this article, you’ll know:
- How smoke and carbon monoxide detectors work
- Where to install them for the best coverage
- What to do if one ever goes off
How Smoke and Carbon Monoxide Detectors Work
Smoke detectors are designed to warn you at the earliest sign of fire, often before you can see or smell smoke yourself. Inside, they have small sensors that react when smoke particles enter the chamber. This quick response gives you precious extra time to get out and call for help.
Carbon monoxide detectors are built for a completely different threat. Carbon monoxide (CO) is an invisible, odorless gas that can build up from things like malfunctioning furnaces, gas stoves, or running vehicles in attached garages. Because you can’t see or smell it, the only way to detect it is with a CO alarm that constantly monitors the air.
Even though both devices are called “detectors,” one will not do the other’s job. A smoke detector won’t warn you about CO, and a CO detector won’t warn you about fire. That’s why you need both in your home, working together to cover different dangers.
Are Your Detectors in the Wrong Spot?
Even the best detectors won’t protect you if they’re installed in the wrong place. These are the issues we see most often in Iowa homes:
- Too close to kitchens or bathrooms – Steam from showers or smoke from cooking can trigger false alarms, leading some homeowners to disable the detector completely.
- Carbon monoxide detectors near vents or windows – Airflow can push CO away from the sensor, making it less likely to detect dangerous levels.
- Mounted at the wrong height – Smoke rises, so smoke detectors belong high on walls or ceilings. CO detectors vary; some are best at eye level, others higher up.
- Units well past their replacement date – Most detectors last 7–10 years before the sensors lose reliability, even if the alarm still works.
Where to place them for best coverage:
- Smoke detectors – One in every bedroom, one outside each sleeping area, and one on every level of the home (including the basement). Place them high on walls or ceilings, away from air vents.
- Carbon monoxide detectors – One on every level of your home and near each sleeping area. Follow the manufacturer’s instructions for mounting height.
Keep all detectors out of corners, away from fans, and clear of windows where drafts can interfere. Take Dave, for example, he mounted his carbon monoxide detector right next to an air freshener. Now every time it beeps, he has to wonder if it’s saving his life or just really hates lavender.
Having the right detectors in the right places is one of the simplest ways to protect your home and family. And once you know how each device works and what to do when it goes off, you can react with confidence instead of panic.
Of course, detectors have a way of speaking up when nothing’s wrong, too. If yours has started chirping and it’s driving you up the wall, have a professional come out to take a look. Sometimes they don’t chirp for any reason at all; other times it can be rooted in a bigger problem.
What to Do if an Alarm Goes Off
When a detector starts beeping, your reaction time matters. The faster you respond, the safer you’ll be.
If a smoke detector goes off:
- Get everyone out of the house immediately.
- Call 911 from a safe location outside.
- Don’t go back inside until the fire department says it’s safe.
If a carbon monoxide detector goes off:
- Get everyone out into the fresh air right away.
- Call your local fire department or 911.
- Don’t re-enter the home until it’s been checked and cleared.
If the alarm continues to sound and no hazard is found, refer to the manufacturer’s guide. It could be a low battery, an end-of-life warning, or a malfunction, but never assume that’s the case without ruling out a real danger first. If it is just a low battery, congratulations, you’ve survived the world’s most annoying audition for “Beep Idol.”
Stay Protected, Stay Informed
Having the right detectors in the right places is one of the simplest ways to keep your home safe. And once you know how each device works and what to do when it goes off, you can react with confidence instead of hesitation.
If your smoke alarm has started chirping, don’t ignore it. Our guide on how to stop a smoke alarm from chirping walks you through how to quiet the noise, find the cause, and know when it’s time for a replacement.
Frequently Asked Questions
Do I need both smoke and carbon monoxide detectors?
Yes. One will not detect the other’s danger. You need both for complete protection.
How often should I replace them?
Most should be replaced every 7–10 years. Check the manufacturing date on the back. If you find one older than your first smartphone, it’s time for a new one.
Can I get a combination unit?
Yes. Some units detect both smoke and CO. These are great for bedrooms and hallways, but may not be ideal for every spot in the house.
Do they need to be hardwired?
Hardwired detectors are common in newer homes and often have battery backups. Battery-powered units work well too, as long as you test them regularly. Read our guide on Battery vs Hardwired Smoke Alarms
