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

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.

This is a great brand. We purchased two of them for our house. They work as expected if there is a leak it is very loud and very reliable. Would buy over and over.

We purchased two of these units 10 years ago. They were really easy to install and very easy to use. We recently had an ice storm and we’re out of power and had to use generators back in January. Our carbon monoxide detector went off in one of our rooms, but it was one of those that just beeped four times. So I grabbed this unit off of the wall and brought it down to that room. The reading went from 0 up to 41 almost instantly. It basically lit up like a Christmas tree, and I immediately opened up all the doors and windows in that room and would periodically check very quickly to see if the number was going down and it did. It went all the way down to 0. So the fact that this has that digital read out on it with actual numbers was very important for peace of mind. It’s great that the other unit went off (also made by Kidde), so that it initially alerted us to the danger of carbon monoxide, but to have a display actually show you tangible numbers was very important. They say that these have a battery life of 10 years. As I mentioned first in this review, we bought two of these units 10 years ago. One of the alarms started beeping 3 times one evening about four days ago. When I looked at the unit, it displayed “End” on it and upon looking up what that meant. It literally means the unit isn’t the end of its lifecycle and needs to be thrown away. I had written “4/26” on the unit 20 years ago, so it literally lasted 10 years and one month. And tonight, the other one gave its last battle cry of 3 beeps and displayed “End.” So we have given it a proper goodbye and ordered a replacement that will arrive first thing in the morning. I had a family member pass away from carbon monoxide, so we take this very seriously and this unit gave us the ultimate Peace of mind. Whoever as Kidde tested and designed this deserves a raise! They nailed the 10-year lifespan! :) Thanks, Kidde!

I think it works? I haven't had any alarms or readings on display, but I haven't woke up dead either!

The Kidde Carbon Monoxide Detector is one of those small investments that delivers huge peace of mind. After installing it in my home, I immediately felt more secure knowing that my family is protected from something as serious—and silent—as carbon monoxide exposure. Setup was incredibly easy. It took just a few minutes to install, and the instructions were clear and straightforward. The digital display is a nice touch—it gives real-time CO levels, which adds an extra layer of reassurance beyond just an alarm. What really stands out is its reliability and thoughtful design. It has a clear, loud alert that’s hard to miss, and the test/reset button works without a hitch. I also appreciate that it’s battery-operated with a backup option, so it continues working even during power outages. In a world where safety often gets overlooked until it’s too late, this detector provides consistent, quiet protection you can depend on. If you’re looking for an easy-to-use, durable, and accurate carbon monoxide detector, Kidde is a brand you can trust—and this unit proves it. Highly recommended for any home, apartment, or even RV. It’s a small device that could make a life-saving difference.

Simple to install, batteries were included. Was reasonably priced. Well worth the money. To replace with the same one that came with my camper would have been $86.00 SO MUCH BETTER

Have this installed where we use a propane stove for heating which may result in a carbon monoxide leak. Either we don't have a leak, or we do and the sensor doesn't register it. Of the two, I'll guess it's the first The point being there is no way to test it by blowing CO past it, as it integrates CO exposure over time and not instantaneous spikes. The battery lasts for 10 years and the unit will remind you to replace the unit (you cannot change the batteries) when the time is up.

Very simple design. Easy to install

C'est bien ce qu'il a à faire

GOOD

Not working

Bought January 2016. It must count the hours from when it's activated, because it chirped and displayed 'END' at the 10 year mark. (Unfortunate that it was at 4am.)

Good quality easy to install.Would recommend it, arrived on time