Features:

  • Keep your family safe with this hardwired smoke alarm the battery backup means constant monitoring, even if there's a power failure
  • Equipped with an ionization sensor, this smoke alarm reliably detects smoke from fast-flaming fires and alerts you with an 85-decibel alarm
  • To ensure complete protection make sure to place one on each level of your home and in each bedroom
  • Can connect to other compatible BRK or First Alert smoke detectors, to ensure all alarms will sound when smoke is detected
  • Simple to use, with a single test/silence button, and side-load battery compartment tamper-resistant locking brackets and universal mounting brackets make installation easy
  • Rigorously tested to meet UL standards120V AC power with 9V battery backup to keep alarm functioning during power outage
Switch from Kidde to First Alert

Needed to replace 20 expired Firex models, which are now owned by Kidde. Being that market leader, Kidde had ZERO interest in making the job easy and rather than supplying an adapter, was insisting that I rewire each detector with a new harness. Hmm... twenty x 15min each is more time than I care to invest in this project. Then I discovered these nifty items First Alert ADF-12 BRK Smoke Alarm Adapter Plug (Pack of 12) made by their competitor who's obviously interested in taking market share. Literally, replacing each detector was a 2min job. So far so good. I've been living with them installed for about a week and so far, no false alarms as others have reported. My only criticism thus far is that the color is ARCTIC white as opposed to off-white, so for those of us with more modern flat or matte ceiling colors these detectors tend to stand out more than Kidde models. Refer to my pic to see the color difference. Wish First Alert would make an off-white version.

Good buy

We changed out the smoke alarms in our home last summer because the old ones had been in place for more than ten years. Actually, we had a handyman change them out when he was over doing a bunch of other stuff (in part, because we have a couple of really high ceilings and do not have a ladder that is even high enough to reach). He changed them out lickety-split, like a minute or two each. I believe he had to change out the base on them. If you buy a smoke alarm at Home Depot or Lowe's it will cost you considerably more than buying it online--and buying in a multiunit pack (or "contractor pack") online is a special bargain. Also, sometimes at HD or Lowe's the selection is more limited than what you will find online. For example, I recall that they have a wide selection of (more expensive) Kidde brand devices at HD but not nearly as much to choose from by First Alert. I understand that occasionally with pretty much any brand of smoke detector you will get a lemon that beeps even when it has a good battery and even when there is no smoke. In fact, we had that happen a couple of years ago with a fairly new detector--called over a specialist to check it and he said sometimes they just start chirping for no good reason. So this is all the more reason to buy one that is inexpensive--so when you do get a lemon, it's not very painful to throw out the old and get a new one. If you are wondering what detector to get to replace your old one, just pull off the old detector and look at the model number, then Google the model number. Most likely you will find information about whether that model number is still available or whether there is a new model number filling the same role. In our case, the model number had changed in ten years but the new model number was basically the same unit (most builders use these First Alert models or the evidently identical BRK model because they are inexpensive). A rose by any other name would be as sweet, saith the Bard of Avon. Some tips: (1) consider buying an extra detector unit so that if you do have one that goes haywire (starts chirping for no good reason and replacing the battery doesn't fix the chirping), you can easily replace it; (2) you can buy 10-year lithium batteries for about $10/each at Radio Shack (and other places), and if you use these rather than regular batteries, you don't have to change the battery every year (esp. useful for detectors mounted in very high ceilings) (I think this is a better bargain than buying a unit that comes with a "sealed" lithium battery already installed); (3) you might consider writing (such as with a Sharpie) the installation date on the back of the device (the side that is mounted against the ceiling)--this will make it easy to remember in a few years when you installed this particular one. My friends, stay safe, and do not cook a goat indoors on a bonfire for any reason.

Best unit for wired, interconnected systems

I bought seven of these to replace the wire-connected units in my house. A few key advantages over the comparable Kidde PI2010: Most important is that the LED tells you which one sounded the alarm AND which one needs a new battery. If you have ever stood in a house with wired alarms at 2 in the freeekin' morning, trying to pinpoint the damn -bip- every minute, you will know how much swearing this feature eliminates. Trust me: This feature is a must. You would think every alarm would do that, but they don't. Update after a year and a half: They all still work. One false alarmed once for no apparent reason. More notes: - We are supposed to replace smoke alarms every 10 years. - A long list of agencies recommend dual-sensor units that have photoelectric (which are good at sensing flaming fires) and ionization (which detect smoldering fires much faster). This one is dual. - Forget about unit that include a CO detector. Better as separate units because they should ideally be placed differently. - The Nest units have brilliant features but are $115 each (!!!) and are photoelectric only. - If your house is not wired, then use conventional battery-powered units, $15-20. I didn't compare but features to look for are 10-year lithium batteries (which means you never replace batteries, you replace the units); and if not lithium, then easy battery replacement with door on font, to remove without removing the unit; AA batteries rather than 9 V; how it displays that it was the source of the beep, especially for the battery bip that can be hard to pinpoint in the middle of the night; and most important, dual sensor. - Batteries generally last two years in most units (I don't know how this unit will do yet) but keep your life simple and replace them all at the same time, once a year. Because you know that when they fail, it will be at 3 AM. Advantages of the First Alert (BRK) 3120B over the Kidde PI2010: - Kidde reviews suggested some experienced failures. - AA batteries rather than 9 V - Again, the red LED tells you which one is triggering the alert and which needs a battery - Battery door on front of unit Note about wired units: You generally want to replace all at once because wired units from different manufacturers may not work together. Units come with new wiring and bracket. You use wirenuts to wire in the new connector. Easy enough but turn off power first, it's 120 VAC.

Nice quality product.

I was very pleased to find that these switched out easily with my old smoke alarms with one year batteries (same brand). I didn't even need to move the screws or change the wires. Since beeping smoke alarms freak my dogs out, I am glad to know that will happen way less often.

replacing BRK with BRK seems like the right move to me

Installed 6 of these today. Each shipped with 2 Duracell AA batteries dated MARCH 2026- we'll see how long they last. These new BRK alarms replace ionization BRK units from 2004 that used 9V batteries. I didn't have to replace those batteries within the 10-year warranty, so that was nice. Also nice was the existing wiring harnesses worked with the new alarms, even though the models were different. This is a "dual sensor" smoke alarm, which contains the 2 smoke detection types: ionization and photoelectric. This is *not* a "dual purpose" alarm, which contains 1 type of smoke detection and CO2 detection. A few "well-respected"?? manufacturers are advertising their "dual purpose" alarms as "dual sensor" which is NOT CORRECT. For those of you pondering the question, "Why wouldn't everyone want to buy the dual sensor units??" Besides cost, there are 2 factors from what I could extract from my best attempts at researching smoke alarms... 1. Dual-sensor smoke detectors are a bit of an enigma currently. Most manufacturers do not pimp their dual sensor alarms as visibly as their single sensor alarms or their smoke/CO2 alarms because the standards folks cracked down on manufacturers "cheating" the specs by taking advantage of a loophole that exists when incorporating both detection types into a single unit. Maybe I'm stupid, but it appeared to me that BRK was the only manufacturer (that I could find) actively adopting the latest standards for dual sensor units, so "cheating" was not applicable. 2. The latest residential standards need to include at least 1 location at each living level" (basement, main, upstairs, etc.) for a CO2 alarm as well as the standard locations for smoke alarms. Since there is no such thing as a dual sensor smoke + CO2 alarm, you may very well have to choose between either the dual sensor smoke alarm *or* the dual purpose (smoke + CO2) alarm. Alternatively, you could install a CO2 alarm where there was previously a smoke alarm. I'm also learning the strength and brains of the microprocessor determines the reliability of the dual sensor alarm and its ability to prevent false alarms. Thank you for reading, please reply if any inaccuracies are found. I'll update the review when the first batteries start dying. :)

Super easy to swap out and replacements were brand new!

Works as advertised. Easy swap if you already have this style installed. These smoke detectors are designed to last about 10 years. There is a sticker on the back showing date of manufacture. Expect 10-12 years after that date.The house we bought has seven installed. We have been in the house 12 years and they have going out one at a time for past two years. I ordered these thinking for the price they might have been on shelf somewhere for a few years but good price either way. I was surprised to see every one in my order of seven had a manufacture date of a couple months prior to my order. They also all had batteries installed with the plastic "pull here to activate." If yours are around 10 years old and they chirp like battery is dead but new battery doesn't fix they need replaced. Just twist off and unplug and install new ones. Very happy with this purchase.

Took maybe 5 minutes per unit to swap out and worked like a champ straight out

Replace an entire house that had previous BRK 4120B's that were outside of the supported working status and were randomly going off or failing. New units will use old wiring harness from 2120's but you will need to replace the mount ring on the ceiling as they are not the same size however the mounts use the same screw locations so you don't have to back the screws all the way out...just loosen and twist off...twist on new mounting bracket and screw back down. Took maybe 5 minutes per unit to swap out and worked like a champ straight out.

Good smoke alarms, but sometimes they need a hard reset to fix the false low battery alert

I bought a couple of these to replace my old detectors three years ago. I was hoping they wouldn't give me grief when it was time to replace the batteries- the old ones were a little finicky and would still chirp even with brand-new batteries. At 12AM this morning one of these started chirping even though it's battery measured 9.62V. I replaced the battery, and first thing this morning I checked the voltage of the battery in my other detector, which was still working fine, and it was at 9.23V. I did some searching and found that sometimes a chirping smoke alarm needs a hard reset to clear the microprocessor of errors that can cause a false low-battery alert. In order to do this you need to disconnect the unit from AC power, remove the battery, then hold the test button for 15 seconds(it's also a good idea to mute the siren by covering it with your thumb.) You'll hear the alarm sound, then taper off to silence. After doing the reset on the faulty unit I plugged it back in, installed the battery that measured 9.23V, and it's been working fine for several hours- so if you're having trouble with an alarm that still chirps every few minutes even though the battery is good, a hard reset may be the solution.

1-STAR - POOR PACKAGING / 5-STAR PRODUCT FOR SURVIVING SHIPMENT

1-star rating for pathetic packaging. --------------------------------------------------- This is not the first instance this has happened — Amazon Fulfillment packs as many items as hastily as possible into an undersized box leaving the package bursting at the seams. 5-STAR PRODUCT for surviving shipment. --------------------------------------------------- The alarm works, and links with my existing Kidde/Firex dual sensor smokes (which are prematurely failing — 1x1x1 ...). The electrician [prior to my ownership of the home] worked miracles snaking the wiring through 2x4s in order to cram the alarm into a tight space adjacent to a wall (probably not to code, either). I modified a Legrand plastic fixture box in order to mount the now defunct Kidde sensor, and to add more spacing between the detector, the wall junction, wiring, and connectors while improving accessibility. The FirstAlert has it's own mounting ring which is smaller than the Kidde — so, I carefully aligned the First Alert mounting ring (for quick access to the battery compartment), and simply glued the FA ring to the Kidde ring with 5-minute epoxy which holds brilliantly — voilà! Hopefully one doesn't encounter this situation; however, I found this to be an acceptable solution for accessibility — short of a rewire. And, as a bonus, FirstAlert also included a shower cap which is an unbelievable value.

Nice design

This was easy to install. It's so much easier to attach the detector to the mounting plate than my old smoke detectors! I really like the latch feature that makes it easy to identify which detector triggered an alarm or a low battery chirp. I also like that it uses AA backup batteries, which are much cheaper than the 9V batteries my old detectors used. I used these detectors in most of my house. I also put one First Alert BRK SC7010BV on each floor for CO detection. The 3120B is great because it's a dual sensor detector. The two models interconnect successfully so any detector can trigger an alarm from all of the rest. (The compatibility is assured in the 3120B instructions. And I tested it myself, too.) If one of the talking detectors is the one that detects a problem, a voice will announce if it's smoke or CO. If one of the non-talking alarms detects a problem, there won't be any voice announcement. When that happens, we know it must be smoke. UPDATE: I installed these detectors about a year and half ago. They are very, very sensitive. They've gone off twice so far. I'm pretty sure the first time was caused by trace amounts of smoke that entered the house from a fire far away. I could barely smell it, but only outside. I don't know what caused it the second time, but I suspect it was dust because there's a lot of air movement in the room where the alarm was triggered. SECOND UPDATE: The detector that was giving me false alarms is next to a door that tends to accumulate a lot of dust due to the way the HVAC system moves air through the house. The detector is right in the stream of air that leaks around the door when it's closed. I started cleaning the dust of the doorframe and door edges once every few months, and I haven't had a false alarm since then.

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