Homeowners often assume carbon monoxide detectors last forever, but that’s not the case. At All Spark Electric in Fort Worth, TX, one of the most common safety questions we hear is how long do carbon monoxide detectors last and when they should be replaced. Knowing the answer matters, because an expired detector may look fine on the wall while quietly failing to protect your home.
Carbon monoxide is an invisible, odorless gas that can be deadly. Your detector is the last line of defense, so understanding its lifespan, warning signs, and replacement timing is critical for keeping your family safe.
How Long Do Carbon Monoxide Detectors Last?
In most homes, carbon monoxide detectors last 5 to 10 years, depending on the model and manufacturer. The sensing technology inside the detector degrades over time, even if the unit still powers on or chirps during a test.
Most modern detectors clearly list an expiration date on the back of the unit. If your detector is past that date, it should be replaced immediately, even if it appears to be working.
When homeowners ask how long do carbon monoxide detectors last, the safest answer is simple: if you’re unsure of the age, it’s time for a new one.
Why Carbon Monoxide Detectors Expire
Carbon monoxide detectors rely on internal sensors that chemically react to the presence of CO gas. Over time, those sensors lose sensitivity and accuracy.
This happens because:
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The sensing elements slowly break down
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Dust, humidity, and household air contaminants interfere with readings
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Normal electrical wear affects internal components
Unlike smoke alarms, carbon monoxide detectors may not give obvious failure warnings when the sensor weakens. That’s why age matters more than appearance.
Signs Your Carbon Monoxide Detector Needs Replacement
Even before the expiration date, some warning signs can indicate a failing detector.
Common signs include:
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Frequent or random chirping not caused by low batteries
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Trouble resetting after a test
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No response during testing
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Intermittent false alarms
If you notice any of these issues, replacement is usually the safest option. At All Spark Electric, we recommend erring on the side of caution when it comes to carbon monoxide protection.
Battery-Powered vs Hardwired Detectors
When considering how long do carbon monoxide detectors last, it helps to understand the type you have.
Battery-powered detectors are easy to install and commonly last around 5 to 7 years. However, they rely entirely on battery health and are more likely to be ignored when batteries are removed or die.
Hardwired carbon monoxide detectors are connected to your home’s electrical system and often include battery backup. These units typically last closer to 7 to 10 years and provide more consistent protection, especially when professionally installed.
Regardless of type, all detectors must be replaced when they reach the end of their rated lifespan.
Combination Smoke and Carbon Monoxide Detectors
Many homes use combination smoke and carbon monoxide detectors. These units are convenient, but they still have a fixed lifespan.
In most cases, combination detectors last 7 to 10 years, depending on the manufacturer. When either sensing component expires, the entire unit should be replaced.
Homeowners sometimes assume replacing batteries resets the lifespan. It does not. Batteries keep the unit powered, but they do not restore the sensor’s ability to detect carbon monoxide accurately.
Where Carbon Monoxide Detectors Should Be Installed
Proper placement matters just as much as lifespan. Even a new detector won’t protect your home if it’s installed incorrectly.
Carbon monoxide detectors should be placed:
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Outside sleeping areas
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On every level of the home
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Near fuel-burning appliances
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In attached garages or nearby hallways
If your home has been remodeled, appliances replaced, or additions added, it’s worth reevaluating detector placement to ensure full coverage.
What Happens If You Don’t Replace an Old Detector?
One of the biggest risks homeowners face is false confidence. An expired detector may still light up or chirp during a test, giving the impression that it works properly.
In reality, an outdated detector may:
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Fail to detect dangerous CO levels
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Trigger alarms too late
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Miss slow, long-term carbon monoxide buildup
Carbon monoxide exposure can cause headaches, dizziness, nausea, and in severe cases, loss of consciousness or death. A detector that no longer functions correctly removes an essential safety layer from your home.
How Often Should You Test Carbon Monoxide Detectors?
Testing is important, but it does not replace proper replacement timing.
You should test carbon monoxide detectors:
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Once a month
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After replacing batteries
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After power outages
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When returning home after extended travel
Testing confirms power and basic function, but it does not measure sensor accuracy. That’s why knowing how long do detectors last is just as important as regular testing.
When Professional Electrical Help Makes Sense
While battery-powered detectors can often be replaced by homeowners, hardwired systems are best handled by a licensed electrician.
Professional installation ensures:
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Proper wiring and power supply
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Correct placement throughout the home
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Code-compliant installation
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Reliable battery backup configuration
At All Spark Electric, we help Fort Worth homeowners upgrade outdated detectors, replace expired units, and install new hardwired systems for long-term safety and peace of mind.
Government Safety Guidance on Carbon Monoxide Detectors
For general safety standards and recommendations, homeowners can reference guidance from organizations such as the U.S. Consumer Product Safety Commission, the Centers for Disease Control and Prevention, and the U.S. Department of Energy. These agencies provide clear information on carbon monoxide risks, detector placement, and replacement timelines.
Using trusted government guidance helps confirm best practices, but local electrical expertise ensures those recommendations are properly applied in your home.
Final Thoughts on Carbon Monoxide Detector Lifespan
So, how long do carbon monoxide detectors last? In most cases, 5 to 10 years, depending on the type and manufacturer. After that, replacement is not optional—it’s essential.
If you’re unsure how old your detectors are, or if your home still relies on outdated or missing protection, it’s time to take action. Carbon monoxide safety is not an area where guessing pays off.
For homeowners in Fort Worth, call All Spark Electric to help make sure your carbon monoxide detection system is properly installed, up to date, and ready to protect what matters most.
