Model # 21007581

Internet # 202029419

Store SKU # 343598

Hardwired 120-Volt Inter Connectable Smoke Alarm with Battery Backup

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

$14.97 /each
  • Easy to install
  • Access to the battery is well designed
  • Battery backup


Model # 21007581

Internet # 202029419

Store SKU # 343598

Store SO SKU # 198092

FireX i4618 alarm is a 120V hardwire smoke alarm and battery back-up feature. Utilizes ionization technology that may detect fast flaming fires sooner than photoelectric. Install this alarm in your home to provide you and your family an early warning in the event of a fire. Battery back-up feature provides protection even during power outages and the smart hush feature will silence false alarms.

  • Front loading battery feature for easy battery change, no need to remove the alarm from the ceiling
  • Test/reset button allows you to check on the sensor's functionality and cease false alarms
  • 9-Volt battery backup provides protection during power outages
  • Pre-stripped wiring harness with easy off cap provides easy access to wiring components
  • Inter connectable feature with up to 24 devices of which 18 can be initiating
  • Unit is equipped with piezoelectric horn that is rated at 85 dB at 10 ft.
  • 9-Volt battery (21025830)

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,Interconnected 
Commercial / Residential 
Commercial / Residential 
Connector/Contact Type 
Power Source 
Voltage (volts) 
Warranty / Certifications
Certifications and Listings 
1-UL Listed 


Rated 4.2 out of 5 by 124 reviewers.
Rated 5.0 out of 5.0 by Great basic smoke alarm. This is a great basic smoke alarm at the right price. Easy installation and looks good. I have had no nuisance alarms. This alarm is interconnected to all the alarms in my house. If one alarm is activated, they all alarm. November 18, 2013
Rated 4.0 out of 5.0 by Good product Good product but keeps going off if it is near a cooking area. It also was chirping every 30 seconds and it was chirping at midnight. March 7, 2015
Rated 5.0 out of 5.0 by Excellent purchase The installation was non-sense. Just remove the old wiring harness (from the previous or old detector) and replace with the new one. Replace the mounting plate and install the new detector. Finally remove the battery protection tab, close the battery compartment and press the test button. As simple and quick as that. The battery backup feature is a nice addition tho the detector, so you still has protection during a power outage (you may be using candles to light your house). I bought four. Excellent purchase. January 13, 2015
Rated 1.0 out of 5.0 by Buy a better Alarm Bought two of these alarms to replace the orginal detectors that were 30 years old. After only two years of use, one of the alarms started late night and early am false alarms. Following the instructions the alarm was blown out with compressed air on three different occasions. The alarm STILL gives off false alarms. It's made in China and recommended to be replaced every ten years. I only got two years before it failed. May 6, 2015
Rated 1.0 out of 5.0 by 2 of my 6 i-4168 firex alarms failed within one year I installed 6 of these firex smoke alarms and two have failed within 1 year. The defective alarms started chirping about every 2 minutes. The batteries were tested good and there was no dust present. November 7, 2014
Rated 5.0 out of 5.0 by Great smoke alarm Great looking and fairly easy to install. Removed old alarms and replaced with these alarms July 28, 2015
Rated 4.0 out of 5.0 by Smoke alarm with Battery Backup The smoke alarm was easy to install and works fine. Passed the home inspection with no problem. July 27, 2015
Rated 1.0 out of 5.0 by Not Reliable Even When New I replaced two seven-year-old First Alert alarms with these KIDDE Firex smoke alarms I4618. Six hours after the install we had our first "FALSE" alarm. It was a cool (70 degrees) summer night with low humidity. We HUSHED the alarms and then about twenty minutes later it happened again. Took them both down and will return them tomorrow and try something else. These alarms are not reliable. After reading reviews on the HD website and Amazon, it seems lots of folks are having this same issue. July 7, 2015
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