Friday , September 8 2017
Home / Featured / Mark my Words: Do combo CO detectors work?
Atwood CO detector

Mark my Words: Do combo CO detectors work?

Q. We do not currently have a carbon monoxide (CO) detector in our travel trailer. Are there specific units for travel trailers, or would a house unit work? I saw a combination unit for propane/CO. Is this a better alternative? also, how often should propane and CO detectors be replaced? — Dave

A. Carbon monoxide (CO) detectors are a must-have safety item for any RV. Newer RVs with engines or generators are required to have a CO detector installed by the manufacturer, but if your RV doesn’t have one, you should purchase one right away and install it according to the instructions that came with the device.

The RV environment is full of carbon monoxide sources, and every year hundreds of people die or are hospitalized due to exposure to dangerous levels. While a residential CO detector will work in an RV, you are better off purchasing a detector that is certified for use in an RV.

I prefer a detector that has an LCD readout of the current CO level. That way, I can identify continuously occurring low levels of CO that may not trigger an alarm. Sources of carbon monoxide include RV propane cooktops, ovens, unvented heaters and any internal combustion engine. Charcoal and wood fires also produce carbon monoxide.

I am surprised to hear that there is a combination propane/CO alarm as the density of propane is greater than air, so it sinks to the floor. Carbon monoxide is slightly less dense than air, so it tends to rise. If you mount a combination detector near the floor for propane, it will not be in a good position to sense carbon monoxide. I would avoid such a product.

Most propane and CO detectors do have a lifespan of five to 10 years, and most have a self-diagnostic function that will indicate when the detector is malfunctioning and needs to be replaced. If I have a 10-year-old detector or smoke alarm, I replace it based on the “better safe than sorry” rule.

Always test detectors and alarms before each trip starts and at least once a month while traveling. Replace batteries (if battery-powered) yearly. An example of an RV-rated CO alarm with digital display is shown above.


About Mark Nemeth

In 1997, Mark quit his aerospace engineering job and became a full-time RVer. For almost five years he traveled the country while maintaining his website, Mark’s Fulltime RV Adventure ( posting monthly travel logs. Mark now travels part-time and works as the RV Safety Education Director for Escapees RV Club providing technical training at Escapees Boot Camp seminars, as well as assisting in many other areas of the club. He is also technical advisor for Escapees magazine. Learn more about Escapees RV Club at

Leave a Reply

Pin It on Pinterest