When Should You Replace Smoke & CO Detectors? What Colorado Homeowners Should Know

Most homeowners know they need smoke and carbon monoxide (CO) detectors in their home. But testing them, maintaining them, and replacing them are important steps for these life-saving devices. 

How old are your detectors?

If you’re like many homeowners, you may not know. And if your smoke or CO detectors have been on the ceiling for years, simply pressing the test button and hearing a beep doesn’t necessarily mean they’re still within their recommended service life.

For Colorado homeowners, fall is an especially good time to take a closer look at your smoke and CO detectors. As temperatures drop, furnaces, fireplaces, water heaters, and other fuel-burning appliances get more use—and carbon monoxide protection becomes particularly important.

Here’s what homeowners should know about replacing smoke and CO detectors and how to make sure they’re protecting people and pets.

How Often Should You Replace a Smoke Detector?

The general recommendation is to replace smoke alarms every 5 to 7 years, even if they appear to be working properly. Over time, the sensing components inside a smoke alarm can become less reliable because of age and environmental conditions. An audible test doesn't necessarily mean an older alarm will perform properly during an actual emergency.

Where can you find the age of your smoke detector?

Look on the back or side of the alarm for a manufacturing date or replacement date. You may need to remove the detector from its mounting bracket to find it. If you can't determine how old it is, that's a good reason to consider replacing it rather than guessing.

Bell Tip: If you've lived in your home for several years and have never replaced the smoke alarms, don't assume they're in good shape. Previous homeowners may have replaced them—or they may have been there since the home was built.

How Often Should You Replace a Carbon Monoxide Detector?

CO detectors also have limited service life, but the exact replacement interval can vary by manufacturer and model. Some manufacturers specify replacement after five years, while others specify longer periods. The safest approach is to check the manufacturer's instructions and the replacement date printed on the detector. Some newer alarms provide an end-of-life warning when the sensor needs to be replaced.

The National Fire Protection Association recommends replacing CO alarms when the manufacturer's replacement date is reached, when the end-of-life signal activates, and/or when the alarm fails its operability test.

Are Combination Smoke & CO Detectors a good investment?

Many homeowners prefer combination units that detect both smoke and carbon monoxide. They offer convenience with a single device providing two types of protection.

Does a Smoke Detector Need to Be Replaced If It Still Works?

Yes, if it has reached the end of its recommended service life.

A detector can:

• Light up
• Make a sound when you press the test button
• Have a fresh battery
• Look perfectly clean
• …and still require replacement

Think of the test button as a way to verify that the alarm's testing function is working—not as proof that an aging sensor will perform exactly as a new detector would.

How Often Should You Test Smoke & CO Detectors?

The CPSC recommends testing smoke and CO alarms at least once a month. Batteries should generally be replaced at least annually unless the alarm uses a sealed 10-year battery.

A simple safety routine: Check the test button on every smoke and CO alarm monthly. Replace unsealed batteries annually. Replace the unit by the manufacturer's replacement date. And if it fails a test or signals an end-of-life condition, it’s time to replace it.

Where Should Smoke Detectors Be Installed?

Colorado mandates require smoke detectors on every level of your home, both inside and outside sleeping areas. Carbon monoxide (CO) alarms must be installed within 15 ft of bedrooms in homes using fuel-burning appliances or equipment (such as gas stoves, furnaces, water heaters, boilers, or even fireplaces). Hardwired smoke alarms and CO detectors are required after a major renovation. Interconnected alarms are particularly helpful because when one detects a problem, the others can sound as well.

Why Fall Is a Good Time to Check Your CO Detectors

There's a natural connection between fall home maintenance and carbon monoxide safety, as homeowners start turning on fuel-burning furnaces and fireplaces regularly. It's also a good reminder to have fuel-burning equipment maintained according to the manufacturer's recommendations. A CO detector is an important safety device, but it isn't a substitute for properly installed, maintained, and vented fuel-burning equipment.

What If Your CO Detector Goes Off?

Carbon monoxide is an invisible and odorless gas. If a carbon monoxide alarm sounds, get outside to fresh air immediately and call 911 or your local fire department. Do not try to locate the source of the carbon monoxide yourself or reenter the home until emergency responders tell you it is safe to do so. If a fuel-burning appliance is identified as the source, don't operate it again until it has been properly inspected and serviced.

7 Signs It's Time to Replace Your Smoke or CO Detector

Not sure whether yours needs to be replaced? Look for these signals:

1. It's More Than 7 Years Old 
2. You Don't Know How Old It Is – Err on the side of caution.
3. It Gives an End-of-Life Warning
4. It Doesn't Respond Properly to a Test
5. It Frequently Gives False Alarms
6. You've Had a Major Home Remodel
7. Your Home Has Older, Non-Interconnected Alarms

If you're replacing older detectors, ask whether today's interconnected options could provide better protection for your home.

Should You Replace All Your Detectors at Once?

Not necessarily—but there can be advantages to doing so. Different brands and ages of smoke detectors don’t always work well together, especially if they are hardwired or interconnected. Bell’s Master Electrician has experienced detectors sounding off due to incompatibility. Replacing them as a group can make it easier for them to communicate with one another. Further, different brands might use different internal signals and not go off when another signals a fire threat.  If you're only replacing one detector, consider replacing it with a like brand.

Don't Forget Your Electrical System

Smoke and CO detectors are safety devices, but they're only one part of a home's electrical and mechanical safety picture. If you're replacing hardwired detectors, adding interconnected alarms, or making changes to the electrical system, it's important to follow the manufacturer's installation instructions and applicable electrical requirements. And if you aren't comfortable working with your home's electrical wiring, this is a job worth leaving to a qualified professional.

At Bell Plumbing, Heating, Cooling & Electrical, we believe home service should be about more than fixing something after it fails. We like to partner with you for scheduled maintenance, service repairs, and replacement when necessary. Our job is to provide you with a system diagnosis and let you make an informed decision that fits your budget and comfort level.

A Simple Fall Safety Checklist

Before Metro Denver's heating season gets into full swing, take a few minutes to:

☐ Check the age of every smoke detector

☐ Replace CO and smoke alarms that are past the manufacturer's replacement date 

☐ Test every smoke and CO alarm

☐ Replace batteries as recommended

☐ Make sure detectors are on every level, inside bedrooms and outside sleeping areas

☐ Maintain your furnace, fireplace and other fuel-burning equipment

☐ Make sure everyone in your household knows what to do if an alarm sounds

A few minutes of maintenance today can make a meaningful difference when your family needs these devices most. Let the licensed electricians at Bell Plumbing, Heating, Cooling and Electrical know if we can help you with home electrical safety.

Call (303) 731-5469