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Code One

Model # 21006378

Internet # 100128246

Store SKU # 418542

120-Volt Hardwired Inter Connectable Smoke Detector with Battery Backup

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

$15.48 /each


Model # 21006378

Internet # 100128246

Store SKU # 418542

Store SO SKU # 198092

Code One Ionization Smoke Detector with Battery Backup is an ionization-sensing alarm that offers 120 VAC of power with a 9-Volt battery backup for continuous protection during power outages. This alarm can operate as a single unit or as a component of an interconnected system in your home or business. This important safety device has a push-button test capability to check its circuitry, horn and battery and can be put into a hush mode that will silence nuisance alarms. This unit has a tamper-resistant locking feature to help prevent unauthorized entry or theft.

  • Utilizes ionization-sensing technology to detect smoke
  • Sounds warning upon the incidence of smoke
  • Hardwired smoke detector
  • Rear battery install back up
  • Functions as a single unit or in an interconnected system
  • Hush feature temporarily silences nuisance alarms
  • Test button checks unit's electronic circuitry, horn and battery function
  • 9-Volt battery provides protection during power outages
  • Tamper-resistant locking pin helps deter alarm tampering and theft
  • Alarm cap twists on and off for easy battery replacement
  • Appropriate for residential or commercial applications

Info & Guides

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Product Depth (in.) 
Product Height (in.) 
Product Width (in.) 
Alarm Sensor Type 
Alarm Type 
Alarm/Detector Features 
Battery Back-Up,Hush Feature 
Commercial / Residential 
Commercial / Residential 
Connector/Contact Type 
Power Source 
Voltage (volts) 
Warranty / Certifications
Certifications and Listings 
1-UL Listed 


Rated 4.6 out of 5 by 20 reviewers.
Rated 5.0 out of 5.0 by Great replacement! I needed to replace a previously installed hard-wired smoke detector which appeared to have gone bad (replacing the 9-volt backup didn't stop the constant chirping!). I did some research and found that this model was a perfect fit for the base of the previous one (a 1275 ionization smoke detector). It has been almost two weeks since I installed it and I don't hear those 30-second chirps anymore! The price was reasonable and ordering online and picking up in-store was a breeze. I will be using this smoke detector for future replacements! January 3, 2012
Rated 5.0 out of 5.0 by Easy install Worked great for my replacement situation. Base plate has multiple holes to punch to match your existing situation. The red line is capped in case you are not interconnecting the home alarm system together. Had an existing connector so cut the wires off at old alarm and used wire connector caps to connect the black and white wires together. Easy to see green light. Comes with a 9 volt battery. October 28, 2014
Rated 4.0 out of 5.0 by Completely satisfied replaced original without having to change the base, which was important to me March 31, 2015
Rated 5.0 out of 5.0 by Kidde Smoke Detector Very good unit,interconnectable with battery back-up.After 30 years in Fire Department it's the units I have wired in my home. And also very good price! January 30, 2010
Rated 5.0 out of 5.0 by Kiddle Smoke Detector I looked at several smoke detectors at Home Depot before choosing this particular one. It has the best price performance ratio. The instruction booklet is excellent and easy to understand. The detector itself seems to be good quality. As an added bonus it comes with a battery backup already installed. December 17, 2013
Rated 5.0 out of 5.0 by Good product Inexpensive, but not "cheap." They arrived quickly and were a straight-forward to install. The old ones we had we slowly dying after 12 years. So, I replaced all of them in our house with these. They work great. April 30, 2011
Rated 4.0 out of 5.0 by Very good product! I was replacing a fire detector of the same model so no new wiring had to be done. It was a great replacement for the old model and they did some nice updates on the new model. The one very nice feature that they didn't change is the size of the detector so it fit exactly like the old one! Well done! November 4, 2014
Rated 2.0 out of 5.0 by Flashing Red LED is irritating in a bedroom Bought this as a replacement for a 10 year old detector in our bedroom. Installed and tested great. Even came with a battery pre-installed. I thought the Fairly Bright red LED light flashed to indicate all was OK. Apparently it flashes every 20sec or so perpetually. Not something I want to see on the ceiling of a dark bedroom forever. I'm looking for another brand. April 28, 2013
  • 2015-07-27T11:52:17.789-05:00
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Store Exclusive. This item is available for purchase in select stores only.