First Alert Battery-operated Smart Combo Alarm & Google Nest Learning Thermostat - 4th Gen

There’s an app for that.

It was easy to style like that I can have an app on my phone and keep an eye on things. I really like that as I upgrade my old First Alert to the newer ones I can connect them all and they will all go off if one goes off, I had a little smoke in my house from cooking one evening and I got a little quick alert on my phone, letting me know that there was smoke detected but nothing that set the alarm off, which was amazing

Run Away

Would not purchase. We have now had our fourth false alarm, this time at 4:00 a.m., terrifying my family. When one detector alarms, all of the interconnected detectors sound, making the situation even worse. My biggest concern is how difficult the alarm is to silence. The instructions state that if the detector believes the smoke level is too high, the alarm cannot be muted. During a false alarm, that becomes an incredibly frustrating and, in my opinion, poorly designed feature. We were left w...

Easy install, lacking a key feature, for me.

I bought this to replace a Nest Protect that expired after ten good years. Installation and initial setup were quite easy, as this fits the same mounting plate as the Nest. I could have added it to the Nest app, but chase the FirstAlert app instead, getting the same basic functionality. One feature that I really liked about the Nest was the motion sensor light, for nighttime safety at the top of the stairs where it is located. If this had that feature I would add a star. I got a different nightl...

Don't buy it

This thing has so many bad reviews online. I thought they'd improve it by now. Put the batteries in and instantly had a false alarm of smoke. So... So.... Bad.

Constant nuisance

Not against Lowes, but these things are horrible. App is poor and responds poorly. I have returned and replaced quit a few of these since August of '2025, I have ordered some from First alert as well. Constant false alarms on the wired and wireless version, day time, night time, constantly. Most of the time I have to remove the smoke detector, and pull the battery to get it to stop. - Good luck getting First Alert to stand behind their product as well. Don't waste your money on these, noth...

Terrible Product

I purchased multiple First Alert smoke detectors and have been very disappointed with their performance. Over a period of several months, these units repeatedly triggered false alarms in the middle of the night. The alarms would sound without any smoke, fire, cooking activity, or other obvious cause. What makes the issue especially frustrating is that it wasn't limited to a single defective detector. Multiple units exhibited the same behavior, suggesting a broader reliability problem rather tha...

Expensive and cannot trust it

Purchased 4 of these to replace my old Nest Connects. Since installing, We have had repeated false alarms at night. Our hallway unit wouldn’t silence on a false alarm because it said there was too much smoke present to silence (no smoke.. just faulty). Had to detach it and remove the battery to silence it. We’ve had 2 more false alarms since. I’ve had enough… I removed all of them and will order another product. I wish Nest Protect was still around. Never had any issues with those.

Defective by design

False alerts non-stop. Don’t buy! Aside from being a cheaply made Nest Protect knock off with fewer features and cheaper parts (no path light, hard to understand voice) it is reliably unreliable. I have 4 and will be eating the cost and taking a loss of them all.

Great substitute for Nest Protects-Discontined

I have used Google Nest surveillance cameras-Inside & Out, Smart Thermostat & Nest Protects. After researching mightily, I chose this First Alert battery operated Smoke & CO2 detector as it integrates well with my Google Home ecosystem I was impressed that the device came preloaded with AA batteries and the mount for the Master Bedroom did not have to be replaced. The Nest Protects has a handy pathlight that the First Alert did not. I ended up ordering a motion detecting wall plate that saves my...

False Alert Issues & bad app

I purchased 5 of these SC5 units. Within a month these units started giving false alarms. Unit would alarm claiming smoke. These were not near the kitchen, appliances or air vents. The app never provided an alert during the alarm event. Emails would come in hours after an event. Save your money.