Side by Side Comparison of: First Alert

I hope they work, haven't made a sound. Test monthly and they pass. Says to mount at 3ft, but who does that. Looks nuts. Guess my house will have to fill up to alert, but at least I know it will work. Instaaled the second at my MiL house, no complaints!!

The First Alert CO400 came in a timely manner, as always. So far, so good. It fits in a convenient space, and pretty much out of sight, unless you're looking for it. Thankfully, it hasn't gone off. We'll know if there is anything wrong if it does.

A "must have" for your RV. Don't risk your family's safety- this Carbon Monoxide detector is easy to install. You do know that CO and LP detectors have a limited life span, or you should know this. They expire in 8 to 10 years, and must be rep-laced with new. You can spend much more on a CO detector, but why would you? Combine the low price with PRIME 2-day shipping and it's a win-win.

Just what I needed for safety and to pass my real estate inspection. no need to go to great lengths to install, can hang easily with a string from a hook on wall, or just place on top of cabinet, though more permanent installation instructions are included.

Very happy with the function of this detector. Of course, you never hope to hear it go off so I assume since it is quiet and we are all still conscious, the detector is doing its job. The test performed exactly as it should (very loud beep!) And the little light indicator shows it's on. We needed a battery operated detector due to its placement in our hall, and I was very happy it came with the battery too. No complaints!

When the kids were small, our family nearly died when a faulty heating unit filled our upstairs with carbon monoxide. The only reason we escaped was because odd smells are apt to nauseate me, and I woke up gagging. As soon as I was awake enough to realize what was happening, I was able to throw open the windows, get the kids out of bed and get everyone outside. Since that night, I have never been without a carbon monoxide detector, and this is the one I use. I bought this new one recently because I broke the old one's test button. I trust First Alert and can fully recommend it.

I was looking for something reliable and easy to use/install and these carbon dioxide detectors were exactly what I needed. I have one on each level to give time to evacuate if a leak occurs.

It's really quite difficult to review a product like this, due to the fact that you don't want the alarm to ever have to do its job. Thankfully, I haven't had any carbon monoxide issues in the nearly year that I've owned this alarm, but it gives me peace of mind that it is there and if something horrible were to happen, this at the very least provides an extra layer of safety. If the alarm ever goes off, I will update the review to reflect such.

Plugged this in down by our gas furnace and hot water tank in addition to our fire/CO alarms on the upper two floors.A MUST HAVE if not just for added piece of mind. Don't take a chance with the silent killer CO. Michael

I assume it's working, let's get that out of the way. And that assumption gives me security. If it didn't work I'm sure they wouldn't sell it because there would be too many lawsuits. The convenience of sticking it in a wall socket is even better... but the directions limit where you should place it which was pretty limiting in a house with an open floor plan. But I had just the right spot for it, so I was probably just lucky.

Our last alarms by First Alert lasted five and a half years before it was malfunctioning and required replacements. We ordered these as replacements, thinking the price was right for a five year product. This version does not require batteries and simply operates on your wall plug-in which I LOVE because the old ones required batteries. This way, I never get woken up at 3am to replace batteries in my CO detectors. It seems that's when batteries always run out so we are satisfied with this product!!

I bought this after I disconnected my whole house system. I just built a house about 5 years ago and it has a wired whole house carbon-monoxide, smoke detector and heat detector system. This system would go off all the time for no apparent reason and usually at two or three AM. After the 10th time of it going off randomly I disconnected it.One of my good friends is an electrician and he noticed that I had disconnected my wired system and he told me that's fine, but get a CO alarm, so I did. If you don't have one get one, you can't smell Carbon Monoxide and it can kill you.

I have not yet truly been able to test this system and hope never to have to. It was really easy to install and I really like that it's battery powered rather than wired in (makes it so we can put it anywhere that is most convenient rather than where we have a plug or are willing to drill a hole). So far, very pleased!

Hard to review a week after installing, so what I'll say is that the instructions were adequate and I was able to quickly install both units. I'm glad to have them!

Used several of these to upgrade my vacation home to current code - 1 CO detector on each level near every bedroomThey were quick and easy to install and provide added security to my family. Highly recommend.

Can't find any CO detector in CA that need battery replacement on annual basis. All CO detectors sold in CA have the 10-year long term battery inside, and they are more expansive than those units sold in Amazon requiring battery replacement.I have some rental units, I prefer installing CO and smog detectors requiring battery replacement. Mainly, I then have a very good excuse for visiting each property at least on annual basis to replace batteries but also conducting property inspection at the same time.This CO offered by Amazon is very economical. Can't tell it works or not, as I haven't heard that it ever gets triggered by itself (not due to testing). And no tenant ever reports such incident also.

Beware - if you are replacing an older version (2-3 years ago) of this same model, it is NOT the same exterior as the previous CO400 model. The screw holes don't like up in the back and the battery is in a different location (back in the new, front in the old).I'm not sure why First Alert is using the same model number on this newer version if there are so many cosmetic and other changes. Is it that hard to just use a new number??

I just purchased and installed this. My only quibbles are around installation. There's no real template; just a drawing on the instructions, which are an unwieldy size and I didn't want to cut it up. I made my own by running a pencil over the the mounting brackets and then pressing it against a piece of paper. I also found the screw anchors to be quite flimsy; luckily I had others on hand that worked well.

Works fine but my only mistake was I thought it was battery and plug-in. That was my fault for not reading better. They do make a plug in with battery backup too.

Replaced an older unit that started chirping after I think 7 years. No complaints. Didn't know that the chirping was a warning that the unit was no longer working properly, but eventually figured that out. No batteries to replace, which is my preference. It would have been nice if the model has two lights. Green for things are good and red that there's trouble. But the number of these detectors without batteries is very limited so I got this one again.

Con: my central gas furnace is circa 1966.Pro: the carbon monoxide detector plugged in, in seconds.Con: it wont work if the power goes out.Pro: havent had a long power failure for decades.

All you have to do is plug it in. This is a carbon monoxide detector, no battery back up, Does not detect smoke. Plugged into a regular outlet, it has a dim light to let you know that it works and you can test the monitor at any time, looks nice 7 year life, only time will tell how well it really holds up. Quick shipping

As a canned response to a requested review, I state this:This is one of the items that a review is silly to do as I am happy with this product and would have no reason to not reorder in the same mannerIt is a sundry or something I use in everyday life like light bulbs, toilet paper, cereal etcthe only way I would give a bad review is if it arrived busted and if it did that, as a Prime member I get mainly from Amazon and they take care of all issues like that so I'm sure it does not fit this caseExcellent product it works very good

I bought this alarm for travel purposes, after seeing a TV news story about hotel guests perishing from carbon monoxide poisoning. It is small, lightweight, and easy to plug in. I love that it draws its power from the wall outlet, so you don't have to worry about changing any batteries. Unfortunately, this unit is so compact and unobtrusive that I left mine plugged in at the hotel room after heading home -- so if you use yours for travel, remember to pack it before checking out! (I also see no reason why this wouldn't be a fabulous product for home use, as well.)

These are okay. Mounted them at about eye level as we have 9 foot ceilings in our house. I bought one of these same models a few years ago and these new ones look exactly the same with one exception... the mounting holes on the back side are slightly off from the older (but cosmetically the same model). The redone mount holes are annoying.

I had it 8 months and it started beeping once intermittently and I changed the battery. Still continued to beep and I don't know why, does anyone know? Thanks

Works as advertised but the lights are confusing. When are they going to make one with 3 lights? Red, Yellow and green would work great. Can not possibly cost that much.

My RV came with one of these. When I was trying to change the battery, the flimsy little tab that secures the battery door broke. I had to buy a whole new unit as a replacement, since the damage was irreparable. The tab on the new unit is just as flimsy, so be extra cautious.. You have been forewarned.

I bought these to replace the previous model and I'm irritated. The new model's holes are just a little bit further apart than the previous model. So the holes/screws I already have in the wall don't really do any good and new holes need drilled. Not sure why they wouldn't keep these the same from model to model, but hopefully this saves someone the headache.

it arrived today....relatively small (little bigger then my hand). It takes a 9V battery (included). What DOES frustrate me is that I need to drill into my drywall to install it (two 3/16 holes). Now, CO detectors need to be replaced every 5 years or so (?), so, when this one gets replaced, I'll have two holes in a wall I'll have to patch and paint, that is unless I can find the exact same detector to replace this one. Its just creating work for you.In todays age of adhesives (3M tape for example), I find myself wondering why there isn't a simpler mounting option that isn't as destructive to ones house. Why not have a simple bracket that adheres to the wall w/ double sided tape that the unit slides onto. (putting on wall, not on ceiling).Now, I cannot just put tape on the back of the unit and stick it to the wall as to replace the battery you need to flip open the back of it.

Purchased two of these five years ago. After that time, they both went bad beeping all the time even with new batteries. Clean air in the home. Buy them and expect five years out of them.

These are a convenient and inexpensive way to satisfy the nanny state of California.

More complex than necessary. Lots of instructions to read, stickers to place here and there with a place for an "emergency number." Really? is anyone's emergency number not 911 anymore?

I installed a ventless gas heater in the basement and need a carbon monoxide detector order this one without reading the description wish I had this has no battery backup if the power goes out it is useless. Other than that it is well made so I will kept it put this one in the garage and put the one in the garage that does have a battery backup in the basement.

It's hard to "love" a carbon monoxide alarm, and frankly I really don't know if the darn thing works . . . after all, the only time it has gone off is when I've pressed the button on it, just like my doorbell only not as melodious. Having said that, I am told no well-equipped home should be without one of these devices, and who am I to argue?

It's an affordable "plug in" version without any unnecessary display. I just ordered two more of them. However, you should note they crap out less than 1/2 dozen years.

I bought several of these a few years ago. After they wore out, I ordered the exact same model as a replacement, but although the new model is the same size, the drill holes are now in a different place so I must now re-drill the holes in all the locations where the originals were hung. With concrete walls, this is no small task. It is NOT the same device, but they used the same model number.

Randomly was shipped units that require 9 volt batteries, but we had older models of the same model installed that use AA batteries. Even worse, the position of the hangers on the back of the new ones don't match the older ones. So, one can't just switch them out.

Device is compact and the price is right, so those are good aspects. But the test button immediately broke — the plastic piece snapped where it connects to the case. So be careful when pressing the “button” — or opt for a device that has a regular push button that is more durable.

I bought the three pack of these. One of the three had a defective door, so the little door on the front doesn't close - it just kind of hangs down. The other two work as expected. I wouldn't order this brand again. I actually had to order another one for a rental house and went with another brand that I am much happier with. The frustrating part was that since this purchase was for a three pack, there is no way to return just the one defective item - you are supposed to return the entire lot which I was not able to do (had already installed the other two before noticing that one was damaged/defective).

The test flap on the top doesn't work. It stays down, and only once when I tested it (pushing down with all of my force!) did I even get a test beep. Since that one time, I've never been able to get it to do a test beep. I HOPE it would work if I'm ever exposed to carbon monoxide -- I use it exclusively for travel when I'm in hotel rooms. Honestly, I wouldn't waste my money on this product again!

Apparently First Alert is in the process of changing over the units from the 2 AA battery to the 9 volt. I bought this to replace my old unit that gave out after 6 years. The one I got is the 9 volt unit. The battery compartment is poorly designed -- I had to use a utensil handle as a mini crowbar to pry the 9 volt into place. Additionally, the screw holders on the back are wider than the old unit, so I had to drill a new hole. I'm not deducting from the rating for that, but others complained that the template (that I didn't use) that came with the 9 volt unit is apparently from the old AA battery unit where the holes are closer together. Get your act together, First Alert.

We bought this on January 30, 2015. It died in early December 2015. It started emitting three chirps per minute which, per the instructions on the back of the device, means that it's time to replace the unit.

No battery back-up on an important alarm like this?? I didn't even realize a model existed with no battery back-up or I would have looked before I bought it.

We thought we were getting a good reliable carbon monoxide alarm...We've only had it 8 months and it went off, and had to call the fire department to have them come check the levels in the home, only to find out that our alarm isn't working. There were no levels of carbon monoxide in our home. We were told that it needed to be replace and that it's flawed. Supposedly these alarms are intended to work 7-8 years, not months!

Drains batteries quickly. They last about a week. Other wise, it seems to function properly.

This was supposedly new when I purchased it, but the package was opened and obviously wasn't new. Not happy with that!

This over-priced pain in "the sitting area" has an always-on, glaring RED light.*Red lights are commonly used to warn of an immediate danger that requires attention NOW.*NO-I don't have a carbon Monoxide problem. The red light also stayed on for a week when I plugged it in to an outside plug.

I have purchased 5 over the last 2 years. First Alert seems to builds in an obsolescence of about 1 yr, it will start beeping like low battery, but guess what, it is not the battery. I bought 2 of these in early 2017 (January & April) to replace 2 of these I got at the local big-box store in early 2016. The new ones are beeping already (see picture with build date). Do not recommend, wont be buying these anymore, will try Kidde brand that have a 5 year warranty. First alert $20/12 months = $1.66 a month, a Kidde $20/60 months = $0.33 a month. FYI, home alarm systems with Fire/CO detectors typically have a 5/10 yr life.

Two of the three alarms gave a malfunction signal. The troubleshooting guide says replace the alarm and if they are under warranty send them to the manufacture. Don't bet your life on this product!

Didn't work when tested. Waited to long to test,now can't return.

The battery cover is not easy to open. No light to show power to device. Instruction say each minute it will flash. I had to push the test button several times to get a beep. Maybe I need to install new batteries.

I would have given this good reviews, because it is easy to use and I think would probably work correctly, but after having it only a couple of months one unit already started beeping with the ERR code. That code means end of life. The units say they have a 7 year life after start of use. Well, 2 months is far from 7 years, but I checked the manufacture date and it was made in October of 2006, so Amazon is selling 10 year old detectors. and apparently manufacture date does matter, not just start of use.

It took 6 units (the original and 2 replacement orders) to get 2 working units. A very poor quality unit.

Did not go off when house had carbon monoxide almost died junk

Description is very misleading. I ordered what was described as 2 "case of 5", expecting to receive 10 units. Instead, I received two units and not two cases.

We purchase for a new house purchase. Had to have in place for inspection. Really was only like working for up to 4 days no longer works. Because of the processing time for closing I can't return. Very disappointing!!!

Lasted less than a year, not happy. I bought four of these in January and one of them keeps chirping even with a fresh battery change. If expect it to function longer than 10 months.

Did not work and had to return it

this item did not work at all. When plugged in all it did was beep. No matter where I put it. I would not buy another one and not from this seller again.