First Alert 3120B vs First Alert SCO7CN

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

I found a review on Android Central that claimed this alarm connects to the wifi and sends you email alerts. I should have read more closely when I ordered it, because the information on the product on Amazon says nothing of the kind. I should have known that the price was too good for a unit that supposedly connects to the wifi. They seem good quality for what they are

This is a pretty good smoke detector. We ordered six of them to replace increasingly annoying, late-night-chirping, 10 year old units by another manufacturer. We wanted a dual sensor (photoelectric and ionization) detector with 10-year batteries but were unable to find any that fit the bill, and so settled for the 3120B - at least the batteries were AA instead of the more expensive 9 volt. We've had a little trouble with them - the reason for four stars instead of five

These are fine, they do the job. However, when you put the battery in it goes through a setup where you can pick the room that it’ll be installed (so the alarm will say “there’s smoke in the living room”). Anyways, the setup volume is full blast alarm loudness. Why does the setup menu have to be so loud?! Even with ear plugs in, it’s still too loud

Strip 1/2" off the ends of the new wires. In my case, two of the wires were pre-stripped, but the orange interconnect wire needed to be stripped. It is easier to do this before you start installing the detector on the ceiling 4. Remove the old detector from the base by rotating it counter-clockwise

A low battery warning does not need to be full volumn and it does not need to sound like a smoke or CO warning! When the alarm is blasting one naturally assumes leaving the area is the best course. So battery warning drives one from the building? Inappropriate design. BTW Batteries do not always last a year even when installed fresh so expect randomly timed adrenaline rushes, Random alarms seem the nature of all the smoke alarms I've ever lived with and this unit does occasionally blast one out. Bought and installed five of these and never could set the location so that is a wasted feature

Purchased qty 6 of the BRK3120B photoelectric/Ionization, qty 2 BRK SC7010B Carbon Monoxide/Photoelectric, and Qty 1 BRK HD6135FB 135F fixed 15F rise heat detector. All of these are AC/DC battery back-up detectors that are wired off same AC circuit and all have their Orange wires all connected in Parallel as interconnected so any alarm event will sound every detectors alarm. All were tested for this interconnection and all worked as designed. They all replaced FireX G13 20 year old detectors and one older heat sensor

I not only wanted to get a smoke detector, but a carbon monoxide detector as well. This fit the bill as it is both. Works as expected.

The next day, I heard 3 chirps come from the guest room, silent for about 15 minutes, and the 3 more chirps, then nothing for several more hours. This same issue repeats itself in the master bedroom, and my son's room (all units on the upper level of our house). According to the owner's manual, 3 chirps every five minutes means a malfunction and you should replace the unit immediately. I had just barely purchased the units and they're already malfunctioning? My issue with this is that it isn't happening every five minutes, it is completely a guess when the next chirp will be

You can also set up a "location" for the voice command alerts, so it'll bark at you about what location you pick, if any, if there's an alert. Most important, I'm hoping that this newer unit REALLY knows the difference between CO2 and steam from the kids bathroom just a few feet down the hall..