The answer to 'how long does carbon monoxide detector last' is that most carbon monoxide detectors have a lifespan of 5-7 years. These devices contain sensors that degrade over time, so it's important to replace them every 5-7 years to ensure they continue to accurately detect dangerous levels of carbon monoxide in your home.
Carbon monoxide detectors should be installed on every level of your home, near bedrooms, and within 15 feet of each bedroom door. They should be replaced according to the manufacturer's recommendations, usually every 5-7 years. Some models may have a digital display that shows the detector's expiration date, making it easy to know when it's time to replace it.