FireX Hardwired Interconnectable 120-Volt Smoke Alarm with Battery Backup-21007581 - The Home Depot


Model # 21007581

Internet # 202029419

Store SKU # 343598

Hardwired Interconnectable 120-Volt Smoke Alarm with Battery Backup

FireX Hardwired Interconnectable 120-Volt 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
  • Interconnectable feature with up to 24 devices of which 18 can be initiating
  • Unit is equipped with piezoelectric horn that is rated at 85 decibels at 10 ft.

Info & Guides

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Product Depth (in.)  Product Height (in.)  6.25 
Product Width (in.)  6.63 
Alarm Sensor Type  Ionization  Alarm Type  Smoke 
Alarm/Detector Features  Battery Back-Up,Hush Feature,Interconnected  Commercial / Residential  Commercial / Residential 
Connector/Contact Type  2-Wire  Included  Batteries 
Power Source  Hardwired  Returnable  90-Day 
Voltage (volts)  120 
Warranty / Certifications
Certifications and Listings  1-UL Listed 


Rated 4.2 out of 5 by 110 reviewers.
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 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 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 Smoke Detector the smoke detector works fine, the associate at Home Depot was very helpful. September 25, 2014
Rated 1.0 out of 5.0 by Continuous false alarms There is a reason for a "Quick Hush Feature for False Alarms" on these units. I would not recommend this smoke alarm to anyone that likes their sleep. It constantly went off with false alarms. And with them being hard wired together, the whole house rang out when one would go off. After following the directions from the company and from posts of people who complained, I still kept getting them. Although they may be fairly priced, they are not worth the headache. November 13, 2013
Rated 5.0 out of 5.0 by EASY TO INSTALL Easy to install. Great purchase price. Hardware mount is universal. April 7, 2015
Rated 4.0 out of 5.0 by "Exact" replacement for builder installed smoke detector The old detectors were 11 years old and they kept chirping even after replacing the battery. It turns out that is the "end of life" audible warning. Smoke alarms have to be replaced every 10 years and sometimes sooner. The i4618 is the "upgraded" replacement for the builder installed smoke detectors. It looks identical to the old ones. The old ones had changed to an ivory color from white. By building code there are 7 detectors in my home (living room, family room, bedrooms and hallways). Firex was bought out by Kiddie years ago and changed the connector and mount ring. So, I had to replace the mount ring and change the connector...and no more chirping! Be sure to turn off the AC power before replacing the smoke alarm/detectors. Depending on how high your ceiling is and tall you are you will need a step stool or ladder, a screw driver, and some wire nuts, just in case. It was not not a big deal to replace the mount ring and included connector pigtail. Just loosen the screw enough to turn the old ring to the large hole that lets the ring fall over the screw heads. Then pull down the connector, unscrew the wire nuts one at a time and install new connector. If your detectors are interconnected, connect red wire to the (in most cases) red or third wire. If the detectors are not interconncted, leave the "cap/cover" over red wire. Do not connect red wire to the bare or green wire which is almost always safety ground. Sometimes DiY'ers to save money (or using some wire they have left over) will use the ground wire as the third wire. Check all the smoke detectors and verify that the bare or green wire is isolated from (not connected to) safety ground before connecting red wire to it. Connect white wire to neutral (usually white) and black wire to hot (usually black). Sometimes wire nuts come apart when "unscrewing" them from the wires. It happened this time, but fortunately I have a few wire nuts in my tool box. To take off the inside "heli-coil" off the wire may require a pair of pliers. If you do not have wire nuts in your tools or stuff purchasing a varity box of wire nuts is a good idea. They are only a couple of bucks and you'll end up spending that on gas going back to the store. Push back wires into electrical box leaving connector dangling in the middle. Insert new mount ring over screw heads and twist to securing location and tighten screws just until snug. Tighten the screws too much and you will break the mount ring. Install connector into back of smoke alarm. Place detector on mount ring and twist until detector locks into place. Remove cardboard battery preserver and close battery compartment door. That's it, your done with that smoke alarm. Repeat until all alarms have been changed out. And DO NOT FORGET to turn AC POWER BACK ON! Otherwise, back-up battery will have a very short life. It took about 5 minutes each with my son helping, bring the new detectors and taking away the old ones. You should not have to change them again for 10 years. Once a year with the dusting attachment on the vacuum cleaner clean the opening and around the smoke alarm to reduce false alarms and keeping the alarm working properly. If some "kitchen smoke" gets to the alarm, just use a piece of cardboard to fan fresh air into the smoke detector. This new version has "smart hush". Hold down the button for 3 seconds or so and it silences the alarm for 8 minutes and LED flashes red. I have not had the chance to use the hush feature yet. A note: the smoke detector come with a carbon 9V batteries, which wil last about 6 months. I purchase 9V alkaline batteries on-line from a place in Brooklyn NY. Alkalines last about a year, that's why I use reminds me to vacuum the smoke alarm when replacing the battery. If you can afford Lithum, they should last around 5 years. But you will still have to vacuum smoke detector yearly. This detectors meet the building codes in most areas, but safety experts say you should have a dual ion and photo detector. Ion (this alarm) is good for fast moving smokey fires, where as photo is better for slow or smoldering fires. I'm a single dad, so I opted to replace alarms with what "meets" code because replaing all 7 alarms with dual detector would cost around $230. I price matched the i4618 and replace all the alarms for under $100. If you can afford it install the Kiddie PI2020, it installs on the same wires and protects your family to a higher level of safety. The back-up battery installs in the back (lithium might be good choice here). I can fully recommend the Kiddie Firex i4618. The last ones lasted the full ten years and pretty sure these will last 10 years too. November 19, 2011
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