Do I need a carbon monoxide detector, and where do I put it?

What's happening

Carbon monoxide (CO) is produced by fuel-burning appliances -- furnaces, water heaters, gas stoves, fireplaces -- and by vehicle exhaust in an attached garage. It has no color, smell, or taste, so a person in the home has no sensory way to notice it building up.

Why it matters

Because CO can't be detected by human senses, a working alarm is the only practical way a household finds out it's present before it reaches a dangerous level -- there is no other warning sign to rely on.

What kind of solution

A standalone CO alarm is the standard answer. The main choice is battery-only (nothing to plug in, and it keeps working through a power outage by design) versus AC plug-in with battery backup, which more often adds a digital PPM display or a visual alert aimed at hearing-impaired or deaf users. Every CO alarm reviewed on this site is checked against the same standard its manufacturer cites (UL 2034), though see each review for exactly what has and hasn't been independently confirmed.

Next step

Compare the currently-reviewed CO alarms to see how a battery-only model and a plug-in digital-display model differ, or go directly to the Kidde C3010 review if you already know you want a simple, battery-only alarm.