BRK First Alert 9120BFF/ SMI100-AC Smoke Detector, Hardwired Alarm with Battery Backup, White, 1-Pack

I researched various brands of smoke detectors and decided based on reviews and other factors (UL ratings) that the First Alert / BRK brand was the best and most reliable. I also read about ionization vs photoelectric sensors, and that many different websites recommend having a smoke detector that has both types of sensors installed in a single unit to alert to both types of common house fires (smoldering vs rapid flame combustion). I found the First Alert model smoke detector with both ionization and photoelectric sensors would not work in my application, as the combination sensor smoke detector is battery powered only. The smoke detector configuration in my home is hard wired. So I decided to purchase the First Alert Model SMI 100-AC, which has the ionization type sensor only, and is equipped to be hard wired and has 9 volt battery backup. The smoke detectors I was replacing were USI brand and the old pigtail was not compatible with the First Alert brand. So all 7 of my smoke detectors needed the new hire wire pigtail installed that comes with the First Alert detector. I found this job to be very easy and instructions for installation were very straightforward. Took me a total of about 2.5 hours to rewire all pigtails and install all 7 new detectors. I tested each new detector individually as each was installed, and then again as an interconnected series across the complete circuit. All worked perfectly and all are showing solid green LED, which indicates they are all receiving AC power and alarm and battery backup are working and active. The green LED light is very subtle and does not cast any light at all in a dark room that would be considered bothersome or glaring. Very happy with my choice and I highly recommend to anyone needing to install new smoke detectors or replace old ones that have reached end of life like mine.

These smoke detectors are the exact replacement for our 20-year-old malfunctioning alarms. They are the same brand, and we only had to replace the base plate. The "pigtails" were also the exact same and included in the package, but we were able to use the original ones so it was easy to just replace the baseplate then plugin the pigtail and apply the new smoke alarm then test. All 4 alarms were then communicating when pushing the test button. Would recommend!!

Arrived on time and as expected. Has a green light that glows at night

Very difficult to line up pins, very snug, hard to insert into prior female ending of electrical connection.

Ok, so I ordered this as a replacement for the same detector I bought last year, only thing is the detector I bought last year was really ok. one room in the house (replaced 8) would chirp randomly at night, i replaced the battery and it did not help. so I ordered this one, put it up, and the chirp continued. Further research and investigation did not help, until I heard the chirp again in this spare bedroom. Turns out somehow a battery operated detector with a 2022 date on it was in a spare dresser drawer. Did travelling relatives bring their own, then leave it behind when staying with us? It is a mystery, but these detectors are fine.

Easy installation

Very easy to install

Best value on the market. We have an entire hardwired system and replacing is expensive. This brand is durable and long lasting. It’s also very loud (the system goes off when a sensor is ready to be replaced)