







🚨 Stay safe, stay savvy — the CO alarm that works as hard as you do!
The FIRST ALERT CO250 is a battery-operated carbon monoxide alarm featuring a highly accurate electrochemical sensor, an 85dB alarm, and two silence functions to mute alarms and low-battery chirps. Designed for easy wall or ceiling mounting with included hardware, it includes tamper-resistant features and complies with major safety standards, making it ideal for residential and institutional use. Its compact design and hassle-free installation provide reliable, no-fuss protection against carbon monoxide hazards.










| ASIN | B0039QEV4S |
| Alarm | Visual |
| Batteries | 1 9V batteries required. (included) |
| Batteries Included? | Yes |
| Batteries Required? | Yes |
| Battery Cell Type | Alkaline |
| Best Sellers Rank | #31,301 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #76 in Carbon Monoxide Detectors |
| Brand | First Alert |
| Color | White |
| Customer Reviews | 4.7 4.7 out of 5 stars (2,035) |
| Date First Available | February 24, 2010 |
| Finish | No Finish |
| Global Trade Identification Number | 00029054003928 |
| Included Components | Electrical & Heating;Rough Electrical;electrical-timers |
| Is Discontinued By Manufacturer | No |
| Item Package Quantity | 1 |
| Item Weight | 6.2 ounces |
| Item model number | CO250B |
| Manufacturer | First Alert |
| Material | Carbon |
| Mounting Type | Plate Mount |
| Number Of Pieces | 1 |
| Number of Items | 1 |
| Part Number | CO250B |
| Pattern | Detector |
| Power Source | Battery Powered |
| Product Dimensions | 1.6"D x 4.25"W x 4.25"H |
| Sensor Type | Electrochemical |
| Size | 1-Pack |
| Sound Level | 85 Decibels |
| Style | 1 Pack |
| UPC | 029054003928 |
| Voltage | 120 Volts |
| Warranty Description | 7 Year Limited Warranty |
E**S
Reliable, Easy-to-Use Carbon Monoxide Alarm
Reliable, Easy-to-Use Carbon Monoxide Alarm This First Alert battery-operated carbon monoxide alarm is a straightforward, dependable device that provides peace of mind. Setup was simple—just pop in the included 9-volt battery, mount it on the wall, and it’s ready to go. I like that it’s lightweight and doesn’t require any hardwiring, so it’s perfect for areas where I don’t want to run electrical connections, like a basement or garage. The two silence features are handy. One quiets nuisance alarms (for example, if it gets triggered by something minor), and the other lets you silence the low-battery chirp long enough to replace the battery without the constant beeping. That’s a thoughtful touch and keeps it from being frustrating. It’s not a fancy smart device—no digital readout, no app connectivity—but that’s part of the appeal. Less complexity means less to go wrong. It does exactly what it’s supposed to do: detect dangerous carbon monoxide levels and alert you with a loud alarm. Something to keep in mind: because it’s battery-powered, you’ll need to replace the battery regularly, and like all CO detectors, the unit itself has a limited lifespan (about 5–7 years before replacement). Bottom line: A dependable, no-frills carbon monoxide alarm that’s easy to install and use, ideal for anyone who wants straightforward protection without extra bells and whistles.
C**K
Great Product
Easy to install, works Great!!
L**O
Easy to install
Easy to install . I assume it works as it is supposed to.
D**P
Seems OK to Me
I bought this because I needed only a CO detector, which is surprisingly hard to find, and I wanted one that fit in the location where I already had one installed. The detector arrived in a non First Alert branded box, so I thought at first, this was a little Amazon bait and switchero. Upon closer inspection, however, this IS a First Alert product. If you look at the online product listing, it indicates that the device is manufactured by BRK (which is what the box showed.) Anyway, the screw holes on the detector fit the existing locations of my old Kidde detector, which is what was important to me.
T**Y
Good price point. Replacing an out dated RV detector
Seems like a perfect match to the RV version I have. Works as it should. Good price point.
B**L
Trailer replacement.
Fit into trailer. Replaced old unit.
G**A
Great for price.
I had Honeywell CO alarm which had expired recently. A replacement would have costed about $100 and would have fitted in existing mounting. This one was 1/5th the price and was so easy to replace in the place of Honeywell. I had to remove the previous moulding base. This one could use one of the existing holes, and I had to just move the other screw a bit (didn't even have to drill, just used a screw driver to screw directly at new location creating the hole while screwing - it held just fine). The whole process hardly took 3 minutes. This unit seems well built and sturdy. For the price you cannot go wrong. I can probably buy 5 of these and cover over 50 years, than buy a Honeywell unit which wouldn't last for a decade. Only con is that it does not have a moulding base which in my opinion would looked more pleasant to eyes; as is it looks bare when mounted in absence of moulding on the base. Also, I should mention the base is connected to the unit via a hinge. Overall great unit at great price, I'd buy again in a heartbeat when my other units expire. I hope this helps.
C**W
Works great
Our fifth wheel detector finally gave out so we reordered the same exact one and are just as happy with it quality as the first one we ordered. The battery lasted a few years before we had to change it and it’s really durable. It was a great price and fit exact to the one we had prior as all the hanging holes were still the same on the back of it.
إ**ي
👍
Trustpilot
2 weeks ago
2 weeks ago