Carbon Monoxide Alarms

Carbon monoxide alarms were not always a requirement in Minnesota. However, when purchasing a home I recommend upgrading to the current best practices. In fact, as a home inspector I recommend going 1 step further. Code and building requirements are a minimum, and there is no harm in going above the minimums.

A Minnesota Home Inspector’s recommendations for carbon monoxide alarm placement:

  • Carbon monoxide alarm installed within ten feet of each sleeping room
  • Carbon monoxide alarms should not be installed at ceiling and wall intersections, corners, or within 3 feet of ventilation ducts
  • Carbon monoxide alarms are recommended to be installed on floors containing fuel burning appliances, such as gas stoves, gas burning furnaces, etc.

A Minnesota Home Inspector’s recommendations for testing and replacement:

  • Recommend replacement when moving into a new home
  • Recommend monthly testing
  • Recommend changing batteries (if applicable) yearly
  • Recommend replacement every 5-7 years

Remember, these are simply my recommendations and they may not be requirements by the authority having jurisdiction in your area.

If you’d like to learn a bit more about the requirements Minnesota provides for carbon monoxide alarms I recommend going here.

What is carbon monoxide?

Carbon monoxide (CO) is made up of one part carbon, and one part oxygen, unlike carbon dioxide (CO2) which is made up of one part carbon and 2 parts oxygen. Both CO and CO2 are naturally occurring on the planet, and while CO2 is a requirement for plant and animal life, carbon monoxide is most often the result of oxygen-starved combustion of fuel burning appliances. Carbon monoxide is one of the most common types of fatal poisoning in the world.

Carbon monoxide alarms

Roughly .1 ppm (parts per million) is the current average level of carbon monoxide on the planet. CO alarms are time-weighted, meaning their response time’s will vary based on levels of carbon monoxide in the air as well as exposure times.


Carbon monoxide poisoning can present itself with a number of symptoms, including headaches, nausea, dizziness, fatigue, and convulsions. If you suspect you are experiencing systems of carbon monoxide poisoning it is recommended to you immediately leave your home and call 911.

For more information on carbon monoxide alarms, symptoms, and exposure levels, check out the Kidde website.