First Alert Battery Powered Carbon Monoxide Alarm-CO400 at The Home Depot
Free shipping

First Alert

Model # CO400

Internet # 202433876

Battery Powered Carbon Monoxide Alarm

First Alert Battery Powered Carbon Monoxide Alarm

This item has been discontinued.
The Home Depot no longer carries this specific product.

$19.97 / each
Item cannot be shipped to the following state(s): AK,GU,HI,PR,VI


In Stock



Model # CO400

Internet # 202433876

The First Alert CO400 battery powered carbon monoxide detector with mute button is an easy-to-install, UL-listed alarm that combines advanced technology with a user-friendly design. Symptoms of carbon monoxide poisoning are like the flu, and you might not even know you're in danger. That's why a carbon monoxide alarm is an excellent way to protect your family. It detects the CO you can't see, smell or taste in the air. A single button tests alarm functions and mutes nuisance alarms. This alarm uses an electrochemical carbon monoxide sensor, which is the most accurate technology available. With battery backup, you will have peace of mind that the alarm will continue to work even when the power goes out. It's esthetically pleasing premium shape is ideal for placing in all visible location. The easy loading back access battery door allows you to quickly and easily change the alarms single 9-Volt battery. 5-year limited warranty. Meets UL standards and is code compliant.

  • Battery powered carbon monoxide detector
  • Single button tests alarm functions and silences nuisance alarms
  • EZ access back loading battery door for 9-Volt batteries
  • Low battery warning
  • End of detector life timer
  • 9-volt battery included
  • Utilizes an electrochemical sensor, the most accurate technology to detect carbon monoxide
  • 5-year limited warranty
  • Meets UL2034 standard
  • Loud 85db alarm
  • America's most trusted brand in home safety
  • Note: Product may vary by store

Info & Guides

You will need Adobe® Acrobat® Reader to view PDF documents. Download a free copy from the Adobe Web site.


Alarm Type  Carbon Monoxide  Alarm/Detector Features  No Additional Features 
Assembled Depth (in.)  6.38 in  Assembled Height (in.)  8.56 in 
Assembled Width (in.)  2.29 in  Battery Back-Up  Yes 
Certifications and Listings  1-UL Listed  Commercial / Residential  Commercial / Residential 
Connector/Contact Type  None  Electrical Product Type  Carbon Monoxide Detector 
Included  Batteries  Returnable  90-Day 
Voltage (volts) 


Rated 3.8 out of 5 by 19 reviewers.
Rated 5 out of 5 by This product has a low profile and installs easily into any environment. This carbon monoxide detector has a mute button and is easy-to-install, not to mention it was priced right. April 30, 2013
Rated 4 out of 5 by Dead Battery; Orange "ok" light. Battery supplied with detector was dead on arrival. It is also disturbing that it has an orange flash indicating its working rather than the green normally seen on smoke detectors. Orange usually indicates something is wrong. August 19, 2014
Rated 4 out of 5 by clean and simple. easy to install Product delivered to store according to schedule. Easy pick up and met competitors price, although it was a tedious process to accomplish this. Would order store delivery again April 23, 2014
Rated 5 out of 5 by I love it Very easy to install, directions were great. Looks good. May 13, 2014
Rated 5 out of 5 by Good product Was all I expected it to be. Have these items in my home already, just adding more. Am very pleased. May 9, 2012
2 3 >>


Standard Shipping includes delivery by small parcel service. Processing time varies by product.

If product is eligible for shipping to AK, HI and US Territories additional transit time and remote surcharges may apply.