Kidde Worry Free 10-Year Lithium Ion Battery Operated CO Alarm-21009718 - The Home Depot
Message to Our Customers


Model # 21009718

Internet # 203728675

Store SKU # 151038

Worry Free 10-Year Lithium Ion Battery Operated CO Alarm

Kidde Worry Free 10-Year Lithium Ion Battery Operated CO Alarm

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

$39.97 / each


Model # 21009718

Internet # 203728675

Store SKU # 151038

Store SO SKU # 198092

Kidde 10 year Worry Free Carbon Monoxide will provide you and your family with a loud warning signal against the dangers of elevated carbon monoxide levels in your home. No more waking in the middle of the night to the dreaded mid-night chirp when you install this worry-free alarm that is powered by a ten year sealed long-life lithium battery. With this alarm monitoring your home for carbon monoxide you and your family are protected from the dangers of the silent killer, even during power outages.

  • Kidde 10 year carbon monoxide alarm is maintenance-free; never replace a battery during the alarm's operating life, in addition to the benefit of maintenance free, batteries are sealed, no need to worry about them being removed
  • Features an end-of-life signal that alerts you when it is time to replace the alarm; signal chirps every 30-45 seconds when alarm needs replaced
  • Money savings, no batteries to buy and replace every six months, save up to $40.00 over the life of the alarm
  • Alarm is equipped with test – reset button, tests the circuitry and horn and resets memory after alarm has sounded
  • Alarm is UL listed and is equipped with a piezoelectric horn that is rated at 85 decibels at 10 feet and electrochemical sensor that last 40% longer than other carbon monoxide alarms

Info & Guides

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


Product Depth (in.) 
Product Height (in.) 
Product Width (in.) 
Alarm Type 
Carbon Monoxide 
Alarm/Detector Features 
10-Year Battery,Tamper Resistant 
Battery Back-Up 
Commercial / Residential 
Commercial / Residential 
Connector/Contact Type 
Power Source 
Voltage (volts) 
Warranty / Certifications
Certifications and Listings 
1-UL Listed 


Rated 4.7 out of 5 by 37 reviewers.
Rated 5.0 out of 5.0 by Super easy install What an easy install it was! Just 2 screws into the back plate to the wall and slide the CO alarm in. That's it. Nothing difficult at all. With a 10-Year battery I don't have to worry about it. There is no battery to change when the battery does die out. You would just buy a replacement. A quick tip, make a calendar reminder on Google Calendar or whatever app you use to check on it 10 years from now. July 27, 2014
Rated 5.0 out of 5.0 by Piece of mind and 10 year battery. Great deal. Piece of mind and keeps on working for up to 10 years of continuous protection. I have an older heating system and also use a secondary heating unit which is a wood pellet stove in the family room over the winter months. I am always concerned about the possible buildup of the deadly carbon monoxide gas in my home. Better safe than sorry. This small wall mounted unit is easy to install and sets up as soon as you mount it on its wall mount. Two screws hold it in place and then let it do the work for up to the next ten years before the lithium battery wears out and replacement will be required of the alarm system.I mounted this unit in my living room. I like its modern sleek look and compact size. It is not an eyesore and placed in plain sight and can be heard from anywhere in my home should the alarm sound it can be heard to alert us of danger May 16, 2014
Rated 4.0 out of 5.0 by very convenient They were very install to install. I used the 3m removable hanging strips so I could move them if necessary. I've only had them for a few months, so I can't say whether they will last for 10 years. April 8, 2015
Rated 5.0 out of 5.0 by Worry Free, Sleek Design I worked with a volunteer firefighter who had asked me if we had a carbon monoxide alarm in the house, saying no, he then suggested that we should install one. I did on his recommendation, that was 14 years ago. Thank goodness we never had the alarm go off. The CO alarms do have to be replaced periodically and when the opportunity arose to replace it with an another Kidde who could say no. The model C3010 has a ten-year battery that is not replaceable. Simple to switch on, just slide the back plastic plate into place and it's activated, you'll hear the alarm letting you also know that it was activated. It comes with easy to follow instructions, in English and Spanish, on what carbon monoxide is, installation, and maintenance. Just as you would not be found dead without a smoke alarm you should feel the same about a CO alarm. August 21, 2014
Rated 5.0 out of 5.0 by Easy to install and no worries I like that I don't have to worry about changing batteries March 25, 2015
Rated 5.0 out of 5.0 by Extremely happy I purchased these items ! I purchased 2 CO Alarms ... one for upstairs near bedrooms and one for the main level of my small town home. I am so very happy to have these ... they replace the ones I had that worked just fine, but needed to be plugged in ... both covering the entire electrical outlet where they were plugged in. It is great to have 10 years of protection and be able to conveniently place them / hang them without monopolizing my valuable electrical outlets. I love the subdued blinking of the tiny green light which assures me that it is working and keeping me safe ! I'm so very happy I have purchased these ! October 28, 2014
Rated 2.0 out of 5.0 by Not easy to figure out how to install. We were unable to figure out how to install the alarm so we decided to return it and get another brand. Actually, we were planning on getting two because we needed to replace one on a different level of our house as well. We returned the item, explaining to the clerk that we had been unable to figure out how to get the alarm installed. Clerk was great -- no problem. She directed us to the aisle where the alarms were located. As we were looking for a different option (there was none), she came to find us. She had looked at our returned alarm and figured out how to get it together. Once we saw how to do it, we took back our original and bought a duplicate. Still was not easy after we got home. However, we finally were successful and feel fully protected. February 17, 2015
Rated 5.0 out of 5.0 by Easy install Directions for installation were detailed clearly and concisely. February 25, 2015
  • 2015-05-27T11:00:57.979-05:00
  • bvseo_lps, prod_bvrr, vn_prr_5.6
  • cp-1, bvpage1
  • co_hasreviews, tv_37, tr_37
  • loc_en_US, sid_203728675, prod, sort_default
2 >>


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.