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First Alert CO400 Carbon Monoxide Detector, Battery Operated

4.6 out of 5 stars 9,824 ratings
Amazon's Choice highlights highly rated, well-priced products available to ship immediately.
Amazon's Choice in Carbon Monoxide Detectors by FIRST ALERT

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Pack of 1
Detector

About this item

    This fits your .
  • Make sure this fits by entering your model number.
  • Keep your family safe with this easy to use, battery operated carbon monoxide alarm; Battery powered alarms provide continuous monitoring of CO levels, even if there's a power failure
  • Features an advanced electrochemical carbon monoxide sensor that accurately detects carbon monoxide levels, no matter where the detector is placed in the room.The alarm sequence should last 5-6 seconds. If it does not alarm, make sure fresh batteries are correctly installed, and test it again. If the unit still does not alarm, replace it immediately
  • A loud 85 decibel alarm sounds when CO levels reach dangerous levels
  • To ensure complete protection make sure to place one on each level of your home and in each bedroom
  • 5-year limited warranty; Equipped with end of life signal chirp, so you know when it’s time to replace the unit for safety
  • All first alert CO alarms are rigorously tested to meet UL standards
  • First Alert has been the most trusted brand in home safety since launching the first residential smoke alarm in 1958 (Based on a First Alert Brand Trust Survey in February 2018)
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WARNING:

CHOKING HAZARD -- Small parts. Not for children under 3 yrs.

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Customer Rating 4.6 out of 5 stars (9824) 4.7 out of 5 stars (14044) 4.7 out of 5 stars (20128) 4.8 out of 5 stars (11303) 4.7 out of 5 stars (1113) 4.6 out of 5 stars (4757)
Price $17.49 $17.99 $14.20 $15.58 $32.49 $35.22
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Color White White White White 2.63 White
Item Dimensions 5 x 1 x 3 inches 3.4 x 1.38 x 5 inches 3 x 7 x 11 inches 2.75 x 1.5 x 4.5 inches 0.94 x 4.75 x 2.63 inches 3.4 x 1.7 x 5 inches
Size Pack of 1 1 pack 1 Pack Pack of 1 1 pack

Product description

Size:Pack of 1  |  Pattern Name:Detector

Product Description

The First Alert CO400 carbon monoxide alarm uses an electrochemical sensor the most accurate technology available. The permanent sensor lasts up to 5 years. It is powered by a 9V replaceable battery giving you peace of mind even during power outages. The test/silence button silences the alarm and allows you to test its functionality. The unit monitors and re alarms if carbon monoxide level persist sounding a loud 85 decibel horn. No installation is required and the attractive design allows the unit to be placed anywhere you need it. It includes an optional wall mount with no outlet required. An audible and visual battery signal alerts you to replace the battery. Pull down action chart has convenient guide on what to do if an alarm sounds. 5 year limited warranty. Ul listed.

Amazon.com

Carbon monoxide (CO) is the leading cause of accidental poisoning deaths in America, yet many people don't know they are suffering from CO poisoning until its too late. Since symptoms of CO poisoning are like the flu, you might not even know you're in danger at first. That's why a carbon monoxide alarm is an excellent way to protect your family. It can detect the CO you can't see, smell or taste in the air. The First Alert CO400 carbon monoxide alarm uses an electrochemical carbon monoxide sensor-the most accurate technology available. The permanent sensor lasts up to five years. It is powered by on 9V replaceable battery giving you peace of mind even during power outages. The test/silence button both silences the alarm and allows you to test its functionality. The unit monitors and re-alarms if carbon monoxide levels persist sounding a loud 85-decibel horn. No installation is required and the attractive design allows the unit to be placed anywhere you need it. It includes an optional wall mount with no outlet required. An audible and visual low battery signal alerts you to replace the battery. Pull down action chart has convenient guide on what to do if an alarm sounds. 5 year limited warranty. UL listed. --Bree Norlander

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Product information

Size:Pack of 1  |  Pattern Name:Detector

Technical Details

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Important information

Bulb Voltage

120 volts


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Customer reviews

4.6 out of 5 stars
4.6 out of 5
9,824 global ratings
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Top reviews from the United States

Reviewed in the United States on August 7, 2017
Size: Pack of 3Pattern Name: DetectorVerified Purchase
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1.0 out of 5 stars nothing worse than this happening in middle of the night
By David H Kim on August 7, 2017
Please read and take note ... look at the manufacture date on them when you get it. I should of read the reviews in detail. Bought a 3 pack, one of them started beeping (5 chirps-end of life) 1 month after installing it, and also after return period. I looked at the manufacture date and it is from Nov 2010. I will throw them all out, nothing worse than this happening in middle of the night. So PLEASE check them before your return period ends.

David
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551 people found this helpful
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Reviewed in the United States on August 3, 2018
Size: Pack of 1Pattern Name: DetectorVerified Purchase
355 people found this helpful
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Reviewed in the United States on August 28, 2017
Size: Pack of 1Pattern Name: DetectorVerified Purchase
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1.0 out of 5 stars Boo! It died already! 150 days old...
By SunnySouthTexas on August 28, 2017
Bought this on 30March 2017, and just before the end of August it died. It began chirping like its battery needed replaced, so we put a fresh coppertop in it. It still was chirping. We stepped outside, to verify that it wasn't alerting us to CO levels. Battery out, battery in, another fresh battery, a third new battery - nothing made any difference. We finally just removed the battery.

Apparently, it's the End Of Life death knell for its 7-year life expectancy. Mine has a mfr date of "2016 Jun 07" stamped in it.
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228 people found this helpful
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Reviewed in the United States on January 19, 2016
Size: Pack of 1Pattern Name: DetectorVerified Purchase
479 people found this helpful
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Reviewed in the United States on September 8, 2020
Size: Pack of 2Pattern Name: DetectorVerified Purchase
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2.0 out of 5 stars If you're buying to match older CO400 wall screws, don't bother.
By Gaboose on September 8, 2020
I only bought these because they were an exact model number match for the CO detector that I just removed since it started chirping at 3am to tell me it was seven years old. I figured, "I'll just buy the one that's certain to drop right onto the existing anchors and screws." WRONG. First Alert has changed just about everything while retaining the model number:
(1) Although the shape of the housing is the same, the front of the device is different. No skin off my back.
(2) The battery compartment is now on the rear, and it's IMPOSSIBLE to open, whereas before it was an easy switch from the front of the unit that didn't even require taking it off the wall.
(3) Instead of two AA batteries, it now requires a 9V, which is at least supplied.
(4) The test/silence button, which used to be thick and robust, on the new model threatened to break with just ONE press.
(5) Worst of all, the screw holes on the back are further apart. Previously 2 1/2 inches, and now 3 5/8 inches. WHY?
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25 people found this helpful
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Reviewed in the United States on September 6, 2017
Size: Pack of 1Pattern Name: DetectorVerified Purchase
59 people found this helpful
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Reviewed in the United States on June 7, 2017
Size: Pack of 1Pattern Name: DetectorVerified Purchase
62 people found this helpful
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Reviewed in the United States on July 21, 2019
Size: Pack of 1Pattern Name: DetectorVerified Purchase
20 people found this helpful
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