Kidde Carbon Monoxide Detector, AA Battery Powered CO Alarm with LEDs, Test-Reset Button, Low Battery Indicator, Portable

I used to work on a fire department and CO (carbon monoxide) alarms that just beeped were the bane of our existence because we often had no idea if it was a false alarm if our gas meters showed no problem. Having a detector with a digital readout removes that uncertainty.Yes, we have seen the CO level above zero because we keep one in the RV and there was a problem with the propane RV fridge. The CO level reached 79 PPM at one point. The "beep only" factory CO alarm just stayed silent.Since the first set lasted 10 years until they expired I figured it was a good idea to buy the same ones again. :)

This is a great detector, easy to install. Note that after 10 years it will give an alarm, and the screen will read end for end of life. That's not because of the batteries, but the sensor. In my case the detector I ordered and installed in Feb 2015 had this alarm in Apr 2025. Fortunately I was able to slide the old detector body off its base screwed to the wall and slide the new detector body on. Only issue I had was after about 8 years it beeped which was caused by the AA alkaline batteries corroding so I had to clean the terminals with DeoxIT and install new batteries. After that no issues to end of life alarm. Looking forward to another 10 years of service from this one.

I bought this 10 years ago and only had to replace the batteries once. We recently had a carpet steam cleaning company working and they left our front door open for the hoses. Their truck was running outside a few feet from our front door to power the machinery and this alarm went crazy. The truck's exhaust was coming into the house. Ironically we have a First Alert CO detector low to the floor tied in to our ceiling smoke detectors and it never went off. And it is much closer to the front door! I need to call them to complain. We never smelled anything so without the Kidde who knows what would have happened.

Placed in key spots up & downstairs. I use separate smoke alarms. One downstairs, one in hall upstairs and one each bedroom. I know over-kill. My son is a fireman! Batteries went dead in Co2 detector's in two years. Wrote when the batteries were replaced on the back cover. A hint. Used better batteries lasted 5 years then gave up the ghost. Over-all, good product but not a ten year life. Meets all local requirements. Better safe than sorry.

Replacement unit for my RV. Works perfectly.

Makes a loud alarm when battery needs to be replaced.....so.....works well.

Arrived on time and in good condition. Add batteries and mount to wall. Easy peasy. I bought 2 and installed 1 on main level and 1 in lower level about a month ago, and the readout on both is 0, so that is great. Would buy from them again.

With emergency products like CO detectors, it's hard to know if they really work unless you're actually being exposed to dangerous amounts of CO. And if a CO detector doesn't work, you wouldn't know; instead, you'd just be poisoned while thinking that nothing was wrong. The only way to really find out if it works is to put it in an airtight container and generate CO.Because I like to play with dangerous chemicals at home, I decided to try this out. Adding formic acid to concentrated sulfuric acid causes the formic acid (HCOOH) to break down into CO and H2O. I got both of these chemicals for less than $10/liter apiece, plus shipping. I put some sulfuric acid into a graduated cylinder and placed it in a 1-gallon airtight plastic container. I then added small amounts of diluted formic acid and rapidly closed the container.Sure enough, it worked! It registered CO concentrations that were well within the ballpark of what I'd expect to get with the amount of formic acid I added (using the ideal gas law to figure out what the maximum CO level would be). In high concentration tests, I found that the alarm goes off within 3 minutes of hitting 500 ppm (which is dangerous but would take several hours to kill, giving plenty of time to get to fresh air). In another test, it went off after about 20 minutes of CO levels around 190 ppm, which is dangerous but not lethal. Its peak reading is in the 910-920 ppm range; it doesn't display levels higher than that. Needless to say, it goes off within a minute or two of such high CO levels and anybody who sees 900+ ppm on the display should leave their house and seek medical help immediately.It worked well in low concentration tests too. Due to some strange US regulation, it displays "0" for any reading below 30 ppm. If you press the "peak level" button, though, it will tell you what its peak reading was even if it was below 30 ppm. This works down to the 10-15 ppm range, below which you don't really have to worry about CO at all. Prolonged exposure around 50 ppm leads to an alarm after a couple of hours.Another, simpler test (which anyone with a CO detector should do to make sure it's working) is to light a candle in an enclosed container with the CO detector, then close the container. The candle will burn through the available oxygen and a fair amount of incomplete combustion (releasing CO instead of CO2) will occur as it runs out of O2. I tried this and got 96 ppm with a small candle in my gallon container; a larger candle would probably release more. I then tried it by lighting a crumpled piece of newspaper in the container and got >910 ppm, which is reasonable because paper and wood experience pyrolysis, which releases lots of CO. Combustion of small amounts of acetone (a fairly clean fuel relative to paper) resulted in 300-550 ppm depending on how hot the fire got before I put the lid on; the lower reading relative to paper helps confirm that it's reading accurately.In conclusion - this $20 detector works very well when tested with real CO. It's accurate, the alarm goes off at dangerous CO levels, it only goes off if CO levels are dangerous, and it might just save your life.