First Alert Basic Battery Operated Carbon Monoxide Alarm - CO400 (1039718)

  • First Alert Basic Battery Operated Carbon Monoxide Alarm - CO400 (1039718)
  • First Alert Basic Battery Operated Carbon Monoxide Alarm - CO400 (1039718)
  • First Alert Basic Battery Operated Carbon Monoxide Alarm - CO400 (1039718)
  • First Alert Basic Battery Operated Carbon Monoxide Alarm - CO400 (1039718)
Battery Operated Carbon Monoxide Detector
Availability: Back Ordered
Regular: $49.95
free shipping online only
*Click For More Details
Price: $21.95
You Save: $28.00 (56% Off)

Basic Battery Operated Carbon Monoxide Alarm

The First Alert CO400 Carbon Monoxide Alarm utilizes an electrochemical carbon monoxide sensor that lasts for up to five years to detect carbon monoxide. This carbon monoxide detector is battery powered, making it portable and easy to use anywhere, even in the event of a power outage. When carbon monoxide levels become elevated, a loud 85-decibel alarm alerts you to the threat.

The Most Accurate CO Sensor Available

The First Alert Carbon Monoxide Alarm uses an advanced electrochemical CO sensor to detect elevated carbon monoxide levels. When CO is detected, the carbon monoxide detector sounds an alarm to warn you of the threat.

Comprehensive Warning Features

When carbon monoxide levels rise, the carbon monoxide detector sounds an 85-decibel siren that is designed to wake even the soundest of sleepers. A low-battery light and alarm alert you when battery power is running low, and an end-of-life timer lets you know when the device should be replaced. Each CO detector lasts approximately five years.

Simple and Easy to Use

The First Alert Carbon Monoxide Alarm is easy to set up. Simply insert the battery, and the CO detector will start to monitor your space for carbon monoxide. There are no complicated displays or settings to navigate. A single button silences the alarm and tests the CO detector. A pull-down action chart instructs you of what to do if the CO alarm goes off.

Where To Place Carbon Monoxide Alarms: One on every level of the home and one in each sleeping area.

First Alert Carbon Monoxide Alarm CO400

Basic Battery Operated Carbon Monoxide Alarm Features:

  • Battery operated, 9V battery included.
  • Mute button, mutes unnecessary alarms. also tests alarm function with same button.
  • Low battery signal mute, quiets low battery signal for up to 8 hours.
  • Electrochemical sensor, most accurate technology available for detecting carbon monoxide* *compared to other common sensing technologies.
  • End of life timer, alarm chirps when it is time to replace it.
  • 9V battery included.
  • Loud 85db alarm.
  • Meets UL2034 standard.
  • Emits T3 Pattern.
  • 5 Year Limited Warranty.
  • Product Dimensions (LxWxH): 3.4 x 1.5 x 5 in.
  • Product Weight: .7 lbs.
Product Specs
Write A Customer Review Review


Average score based on 159 reviews

Rating: 4.9/5Rating: 4.9/5Rating: 4.9/5Rating: 4.9/5Rating: 4.9/5

Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5Homeowner

Reviewed: 08/04/2020 by Bernard Dube

My order came in and seems to be operating well. Thank you

Rating: 4/5Rating: 4/5Rating: 4/5Rating: 4/5Rating: 4/5

Reviewed: 07/20/2020 by Allan Griff

Nothing wrong with device, but was disappointed to find bolt holes not same distance be so I had to put in a new wallbolt. B

Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5Works as expected!

Reviewed: 07/06/2020 by Elisa Goodwin

Received the item on time and it works as expected. Happy with my purchase thus far. One item to note: the placement of the screw holes in this model has changed in recent years, so while I was trying to avoid having to drill new holes by purchasing the same model as I was replacing, I did have to accommodate the change in design.

Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5New CO400 to replace old CO400

Reviewed: 06/01/2020 by Melvin Matter

Very good unit to purchase. One thing to note. The model number was the same as old CO detector we had, however new one would not mount on old mounting brackets. The screws were at different lengths so had to drill more holes in the wall. Would be nice if the model number had consistancy.

Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5First Alert CO-400 Carbon Monoxide Alarm

Reviewed: 06/01/2020 by Robert Nicosia

This new CO detector is excellent. It replaces my previous CO-400 which needed to be retired after 8 years of reliable service. It makes sense to stay with a winner. The First Alert Store was a pleasure to deal with and they had my new detector in my hands within a week.

Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5So far so good

Reviewed: 05/20/2020 by Michael Arden

Seems to be working OK after a month

Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5The very BEST

Reviewed: 05/10/2020 by joseph dillon

Years of use...

Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5Safety first

Reviewed: 04/28/2020 by Michelle Strader

Ordered the First Alert Carbon monoxide alarm because my existing alarm was over 5 years old. Easy user friendly website with fast delivery. Product came as described. Will order direct from them again in the future.

Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5Great detector

Reviewed: 04/27/2020 by Patrick Donofrio

Works effectively.

Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5Replacement purchase

Reviewed: 04/21/2020 by Sahil Patel

I bought this unit to replace an existing unit that had come to the end of its product life.

Rating: 4/5Rating: 4/5Rating: 4/5Rating: 4/5Rating: 4/5Tested out ok

Reviewed: 04/18/2020 by Dan Mattern

Tested ok. Only problem was the mounting screws for my new unit did not match up to the mounting screws for my old unit, even though I purchased the same model type.

Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5

Reviewed: 03/14/2020 by Timothy Carlson

Unit arrived with test button broken it was quickly replaced with a new unit, and while not yet installed, it should be fine.

Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5

Reviewed: 01/01/2020 by susie lorenson

These are very popular. They were sold out in stores i went to. My old one I replaced..chirped 4 times. I didn't realize that was end of its life..however. ..first alert had sticker on the back...stating what the different chirps meant. I like that they put that on there. It also included date is easy to old the unit is. I ordered a three first alert's website. They mailed to me...right away.

Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5Came on time - - all is well

Reviewed: 11/04/2019 by ZVI DERSHOWITZ

No problem installing it

Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5Rating: 5/5No Monox

Reviewed: 09/04/2019 by Richard Murphy

The alarm was the same as the old one I purchased 7 years ago and it installed in the same location. Very easy and reliable to use for years to come.

View More Reviews...
Q: How often do you need to change the batteries?
A: Actual battery service life depends on the particular design of your smoke or carbon monoxide alarm and the environment in which it is installed. All kinds of alarm batteries specified in the user's manual are acceptable replacement batteries. Regardless of the manufacturer's suggested battery life, you MUST replace the batteries immediately once the unit starts "chirping" (the "low battery warning"). It is recommended that you change the batteries in your alarms when you change your clocks for daylight saving time. Also consider replacing your current alarms with 10-Year Life Alarms that never require a costly battery replacement for the ten year life of the alarm. This 10-Year series is available in smoke, carbon monoxide and combination alarms.

Q: How do I get my carbon monoxide alarm to stop chirping?
A: If your carbon monoxide alarm keeps chirping, the battery may be low or weak. On First Alert carbon monoxide detectors, check to see if the battery light is yellow or green. If the alarm is chirping and the light is yellow, it means the battery is low. The way to get a carbon monoxide alarm to stop chirping is to replace the battery.

Q: Where should I install carbon monoxide alarms? What is proper carbon monoxide alarm placement?
A: It is very important to install carbon monoxide alarms near or in each separate sleeping area. Many states now require that a carbon monoxide alarm is placed in each bedroom. For added protection, placement of an additional carbon monoxide alarm at least 15-20 feet away from the furnace or fuel burning heat sources is recommended. Also, install carbon monoxide alarms at least 10 feet from sources of humidity like bathrooms and showers. In two story houses, install one carbon monoxide alarm on each level of the home. If you have a basement, carbon monoxide alarm placement is recommended at the top of the basement stairs.

Q: Is there anywhere I shouldn't install carbon monoxide alarms?
A: Do not install carbon monoxide alarms in garages, kitchens, furnace rooms, or in any extremely dusty, dirty, humid, or greasy areas. Do not install alarms in direct sunlight, or areas subjected to temperature extremes. These include unconditioned crawl spaces, unfinished attics, un-insulated or poorly insulated ceilings, and porches. Carbon monoxide alarms should not be installed in outlets covered by curtains or other obstructions. Do not install in turbulent air-near ceiling fans, heat vents, air conditioners, fresh air returns, or open windows. Blowing air may prevent carbon monoxide from reaching the CO sensors.

Q: How many carbon monoxide alarms should I have in my home?
A: So how many carbon monoxide alarms should you have in your home? The National Fire Protection Association (NFPA) recommends that you should have a carbon monoxide alarm centrally located outside of each separate sleeping area in the immediate vicinity of the bedroom. For added protection, you should have additional carbon monoxide alarms in each separate bedroom and on every level of your house, including the basement. Some states now require that you have a carbon monoxide alarm in each bedroom of the house. If you install only one carbon monoxide alarm in your home, place it near or in your bedroom.

Q: What is the proper way to do a carbon monoxide alarm test?
A: The following procedure is the proper way to do a carbon monoxide alarm test - Press and hold the Test Button on the front of the alarm until the alarm sounds. Be sure you hold the button down long enough; it can take up to 20 seconds for the alarm to respond to the test.

Q: Is it a false alarm when my carbon monoxide alarm sounds and there doesn't seem to be a problem?
A: A carbon monoxide alarm false alarm should not occur if your alarm is in working order. Remember, carbon monoxide is an odorless, colorless gas. If your carbon monoxide alarm went off, it detected potentially harmful amounts of carbon monoxide. After the professionals have evaluated the situation, make sure no one has any symptoms of carbon monoxide poisoning.

Here are a few situations that may cause a carbon monoxide alarm "false alarm:"
  • The carbon monoxide alarm needs to be relocated. Carbon monoxide alarms should be located 15-20 feet away from all fossil fuel burning sources like furnaces and stoves. Alarms should be located 10 feet away from sources of humidity like showers.
  • Fossil fuel burning appliances may not be burning fuel completely. Check pilot lights/flames for blue color. Appearance of yellow or orange flames indicates incomplete combustion-a source of carbon monoxide.

Q: Will carbon monoxide alarms detect explosive gas leaks?
A: No, a single function carbon monoxide alarm reacts to carbon monoxide only. To detect explosive gas, you need an explosive gas detector. Different kinds of explosive gas can be detected and it is recommended that any home that utilizes natural or propane gas have at least one explosive gas leak detector.

Q: I'm ready to change my alarm battery - what replacement batteries can I use?
A: Check your User's Manual or the nameplate on the back of the alarm. Different smoke detectors & CO alarms use different kinds of batteries - 9V, AA, AAA - it all depends on the particular model you have. Use quality batteries like lithium batteries - having plenty of power is worth any extra cost. Never use rechargeable batteries because they may not always provide a consistent charge.

If you are interested in ordering a large quantity of items you may qualify for volume pricing discounts. Volume Discount Pricing is a great way for customers to save big on large, bulk orders of most items available in our store. Please send a bulk order request to our friendly sales staff so they may create a quote and provide personal service for your order! You will receive a response within 1-2 business days and our office hours are Monday through Friday, 8am-5pm CST.
We make it as easy as possible to ensure you get the lowest prices available:
  • Let us know what products & the quantities you are interested in.
  • Get a detailed quote from a dedicated sales rep.
  • Our warehouse ships directly to you.
  • You enjoy the savings & are now a preferred customer.
Send A Request Now
Direct From Warehouse Pricing bulk purchase, wholesale pricing