Smoke and Carbon Monoxide Alarms, Where to Put Them and When to Replace Them (2026 Guide)
Last updated: October 22, 2026.
Disclosure: As an Amazon Associate I earn from qualifying purchases. Some links below are affiliate links, which means this site may earn a small commission at no extra cost to you.
- Put smoke alarms in every bedroom, outside each sleeping area and on every level (USFA).
- Replace smoke alarms every 10 years and test them every month.
- Put CO alarms on every floor and near sleeping areas, and use both smoke and CO alarms (EPA).
- Popular smoke, CO and combination alarms are listed below with Amazon links.
Working smoke alarms and carbon monoxide (CO) alarms are among the cheapest and most effective safety devices in a home. They only help if they are in the right places, powered, tested and replaced on time. This guide summarizes advice from the U.S. Fire Administration (USFA), the National Fire Protection Association (NFPA) and the Environmental Protection Agency (EPA), and lists popular, widely reviewed alarms on Amazon.
1. Where to Put Smoke Alarms
The USFA says to install smoke alarms in every bedroom, outside each separate sleeping area, and on every level of the home, including the basement. It recommends interconnected smoke alarms, so that when one sounds, they all sound. The USFA also says that when you hear a smoke alarm, you may have less than 2 minutes to get everyone outside and safe. NFPA adds that a smoke alarm should be on the ceiling or high on a wall.
According to the latest NFPA research, when working smoke alarms are present in your home, the risk of dying in a home fire is cut by 60 percent. NFPA also says roughly three out of five fire deaths happen in homes with either no smoke alarms or no working smoke alarms.
2. Test and Replace on Schedule
- Test smoke alarms every month using the test button (USFA, NFPA).
- Replace 9-volt smoke alarm batteries at least once every year (USFA).
- Replace smoke alarms every 10 years. The USFA says they need to be replaced 10 years from the manufacture date. Check the date printed on the back of the alarm.
Many “10-year battery” alarms are sealed units that you replace as a whole when the battery is spent or the alarm reaches the end of its life. Read the instructions for your alarm.
| Product | What stands out |
|---|---|
| X-Sense 10-Year Battery Smoke Detector (SD2J0AX) | Sealed 10-year battery, UL 217 listed per the listing |
| X-Sense Smoke and Carbon Monoxide Detector (SC07) | Combination alarm |
| First Alert Battery Combination Smoke and CO Alarm | Combination alarm, battery powered |
See X-Sense Smoke Detector on Amazon →
As an Amazon Associate I earn from qualifying purchases.
See X-Sense Combo Alarm on Amazon →
As an Amazon Associate I earn from qualifying purchases.
See First Alert Combo Alarm on Amazon →
As an Amazon Associate I earn from qualifying purchases.
3. Where to Put Carbon Monoxide Alarms
The EPA says each floor of the home needs a separate CO detector. If you are getting a single detector, place it near the sleeping areas and make certain the alarm is loud enough to wake you. The EPA’s infographic suggests alarms in a central location on every level of the livable space (including the basement) and at least 15 feet away from any fuel-burning appliance, near or inside each sleeping area, and near the door leading to an attached garage and in rooms over the garage. If possible, interconnect your CO alarms, so that when one sounds, they all sound.
Smoke alarms and CO alarms look and sound similar, but they detect two different hazards. The EPA says to install both UL Listed CO alarms and smoke detectors. Follow the manufacturer’s instructions exactly for installation, testing and replacement. The EPA says to test CO alarms regularly (its infographic says monthly, and its Q&A says weekly for battery-powered units), replace batteries at least once a year, and never let anyone borrow the battery.
| Product | What stands out |
|---|---|
| First Alert CO400 Battery-Operated CO Alarm | Battery powered, widely reviewed |
| Kidde Battery-Operated CO Alarm with Digital Display | Digital display |
| First Alert CO400, 2-pack | Two units |
4. Quick Home Checklist
- A smoke alarm in every bedroom, outside sleeping areas and on every level.
- CO alarms on every level and near sleeping areas.
- Test monthly, and write the install or replacement date on each alarm.
- Replace smoke alarms after 10 years.
- Make a fire escape plan and practice it. Working alarms are an important part of it (NFPA).
- If you are deaf or hard of hearing, ask about alarms with strobe lights or bed shakers (USFA, NFPA).
See also our guide to power outage preparedness for generator and carbon monoxide safety.
5. Frequently Asked Questions
How often should I replace my smoke alarms?
The USFA says every 10 years from the manufacture date.
Do I need both smoke and CO alarms?
Yes. The EPA says they detect two separate hazards, so install both UL Listed CO alarms and smoke detectors.
How often should I test them?
The USFA and NFPA say to test smoke alarms at least once a month. Follow your manufacturer’s instructions for CO alarms.
Where should I not put a smoke alarm?
The USFA pictographs say to put smoke alarms at least 10 feet from a cooking appliance, to reduce false alarms.
Is this professional fire safety advice?
No. This is general information. Follow the manufacturer’s instructions and your local fire department’s advice.
Related Guides
- Home Fire Extinguishers, When to Use One, Which Type to Buy and How to Keep It Ready (2026 Guide)
- Space Heater Safety for Seniors, CPSC Rules and What to Look For When Buying (2026)
- Kitchen and Stove Safety for Seniors With NFPA and USFA Cooking Fire Tips (2026 Guide)
Sources
- U.S. Fire Administration: Smoke Alarms
- NFPA: Smoke Alarm Information
- EPA: Where should I place a carbon monoxide detector?
- EPA: Carbon Monoxide Alarms Infographic
As an Amazon Associate I earn from qualifying purchases. This guide is general information, not medical or professional advice. This site is not affiliated with any government agency or product maker.
Comments
Post a Comment