First Alert CO400 Battery-Powered Carbon Monoxide Detector

77 reviews ratings
Walmart #: 001110013
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  • Electrochemical sensor
  • Adds security & safety
  • 1 button tests alarm functions
  • About this item

    The First Alert CO400 Battery-Powered Carbon Monoxide Detector is an easy to use carbon monoxide detector that comes with one carbon monoxide alarm, a user's manual, and two AA batteries. This carbon monoxide detector features a test/silence button that silences the alarm and allows you to test its functionality. The First Alert alarm monitors and re-alarms if carbon monoxide levels persist sounding a loud 85-decibel horn. No installation is required for this carbon monoxide detector, and the attractive design allows the unit to be placed anywhere you need it. The First Alert CO400 Battery-Powered Carbon Monoxide Detector includes an optional wall mount with no outlet required, and is powered by two AA replaceable alkaline batteries giving you peace of mind even during power outages. 5-year limited warranty. Carbon Monoxide alarm meets UL standards.

    Carbon monoxide alarm utilizes electrochemical sensor for increased security

  • First Alert alarm mute feature silences detector when nuisance alarm sounds
  • Single button tests alarm functions
  • Easy front access to the battery
  • Meets UL standards
  • Battery operated, 2 AA batteries included
  • End of life timer, alarm chirps when it is time to replace it
  • Loud 85db alarm
  • Includes manufacturer's 5-year limited warranty

  • Specifications

    Battery Type: Alkaline
    Multi Pack Indicator: No
    Model No.: CO400
    Shipping Weight (in pounds): 0.81
    Assembled in Country of Origin: USA or Imported
    Origin of Components: USA or Imported
    Walmart No.: 1110013

    Customer reviews

    Customer Reviews | 77 reviews | 4.3 out of 5

    4.5 stars

    77 reviews | 4.3 out of 5

    5 stars
    4 stars
    3 stars
    2 stars
    1 stars
    Would recommend to a friend



    Works Great in My Antique Car!

    Customer review by KellydaBelly

    5.0 stars by KellydaBelly

    I bought this detector for my antique car which I suspected was getting some exhaust in the cabin. The possibility of carbon monoxide inside the car worried me. Sure enough when we got the car out on the open road the alarm went off! So now we are having a mechanic look into the possibility an an exhaust leak. So this device works and it is a good value.

    Was this review helpful? (66) (5)
    Thank you! You have successfully submitted feedback for this review.
    Would recommend to a friend? Yes
    Age:45 - 54
    Ownership:2 - 7 weeks
    Usage:Every day
    Just what I needed

    Customer review by Troys98

    5.0 stars by Troys98

    This product is great for placement exactly where you need it. We had a new gas waterheater installed to replace an existing electric. Being that it is gas I felt the need to have this item installed so that if there ever were a problem with the waterheater we would know. I was able to install it in the room right where I wanted it without having to worry about cord placement, etc. Highly recommend.

    Was this review helpful? (33) (1)
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    Salisbury, MD
    Would recommend to a friend? Yes
    Age:35 - 44
    Ownership:2 - 7 weeks
    Usage:Every day
    a very necessary product

    Customer review by theexmichigander

    5.0 stars by theexmichigander

    it is now a law that you must have a carbon monoxide detector, and if it wasn't you would be very foolish not to have them in your home. it was very easy to install, and it was very helpful that the detector came with the batteries including. it was very easy to shop Walmart Online and will be doing it again

    Was this review helpful? (16) (0)
    Thank you! You have successfully submitted feedback for this review.
    Would recommend to a friend? Yes
    Age:65 or older
    Ownership:2 - 7 weeks
    Usage:Every day
    1-3 of 64 total reviews See all

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    by pickymothers 2/14/2010
    • Yes they do. That never appears in ads for them and the state legislatures that force them to be in every home don't seem aware of that. Most are dead after seven years. Some go in three to five. When they reach what the manufacturers call "end of life" they do a beep pattern that sound like that for a weak battery. I had to bring my alarm to the fire station to get them to confirm end-of-life after I changed the batteries twice and both sets of new batteries still made it beep like that. Some manufacturer's websites tell about it. First Alert has a note in their printed instructions that says they "have a limited life." My state passed a CO alarm law seven years ago and right on schedule (but at 2 AM) mine went to end-of-life at that time. Thousands of people are in for a big surprise when their alarms start doing that.
      by OzzieSr5/28/2014
      Was this answer helpful? (1) (0)
    • The promo states the unit will let you know when it's life is over and it needs to be replaced.
      by SylviaII5/28/2014
      Was this answer helpful? (1) (0)
    • NO. Should last indefinitely, although the batteries have to be replaced each year. (The unit actually beeps when the batteries get low, but I would'nt rely on this--just put the battery change date in your calendar). Batteries are easy to change.
      by LivingstonRandy5/28/2014
      Was this answer helpful? (0) (3)
    • The packaging doesn't answer this question but does indicate that dust can cause it to no longer work so suggests not to place in dusty areas.
      by Revel2225/5/2011
      Was this answer helpful? (0) (0)
    • Not that I am aware of, I did have one before I bought this one a few months ago and the only reason I replaced it was I dropped it while moving and it got stamped on, so It broke into make pieces. I had my previous one for about 6years and my mother has never changed hers, she has had it for many years more!!
      by JerseyGirl851/2/2011
      Was this answer helpful? (0) (2)
    • The basic components of an electrochemical sensor are a working (or sensing) electrode, a counter electrode and usually a reference electrode as well. These electrodes are enclosed in the sensor housing in contact with a liquid electrolyte. The working electrode is on the inner face of a Teflon membrane that is porous to gas, but impermeable to the electrolyte. The gas diffuses into the sensor and through the membrane to the working electrode. When the gas reaches the working electrode, an electrochemical reaction occurs; either an oxidation or reduction depending on the type of gas. For example, carbon monoxide may be oxidized to carbon dioxide, or oxygen may be reduced to water. An oxidation reaction results in the flow of electrons from the working electrode to the counter electrode through the external circuit; and conversely a reduction reaction results in flow of electrons from the counter electrode to the working electrode. This flow of electrons constitutes an electric current, which is proportional to the gas concentration. The electronics in the instrument detects and amplifies the current and scales the output according to the calibration. The instrument then displays the gas concentration in, for example, parts per million (PPM) for toxic gas sensors and percent volume for oxygen sensors. Thus, the electrolyte is consumed over time and exposure to CO and will need to be replaced. Solid state detectors are able to last for many years but consume too much power to be battery operated. See: for more information.
      by CCorSeeSee10/16/2014
      Was this answer helpful? (11) (3)
    1-3 of 13 questions See all

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    Product warranty: 5 Years See details

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