Qolsys QS5110-840 IQ Wireless Smoke and Heat Detector

Works perfectly.

Exactly what I needed and easy to install

Was a perfect match to the one I had that needed to be replaced. So far it works with no glitches

These things (Qolsys) are junk, I did my whole house with a Qolsys alarm system and had 5 of these and 3 CO2 detectors. I installed them 5 years ago. The dang batteries lasted longer than 2 smoke detectors and 1 CO2 detector. And the price of these has gone up $30!!!! since November of 2023. I called the company and complained and all they said was, sorry it’s out of warranty. This is getting to be a very expensive alarm system at $80 a pop for these things. I wish I would’ve gone another route with my alarm system choice. The internal switch that tells the smoke detector that it’s attached to it’s mounting plate went bad in 1 smoke detector and 1 CO2 detector and the other smoke detector gives false alarms after 4 years of use.

Great description on the Amazon site. Easy to install and functions very well.

Smoke detectors should be replaced every 10 years. Well, if you own a GE Simon 3 alarm system (and probably other models as well) you probably already know you can no longer buy new GE units. Fear not as these units will work just fine with the GE Simon system. I have replaced all four of my old units with these and feel safe again.

I saw reviews that said that this does not work with a vivint panel, but it did for me. This detector looked identical to my Vivint detector that had expired. I bought this one, and it works perfectly. As long as it matches the appearance of the one you’re trying to replace, it’s a good bet that this one will work. The manufacturer information on the back of this detector is different from my old one that Vivint installed, but that’s not unexpected since the old detector was 10 years old. Just be sure the device itself looks identical to the one you are replacing.

This is obviously a quality made product but customers need to be aware the QOLSYS smoke detector and 2GIG SMKT3-345 smoke detectors may look identical but are not the same electrically. The QOLSYS detector uses Radio Frequency of 319MHz to communicate on, and the 2GIG detector uses Radio Frequency of 345MHz to communicate on, which is where the incompatibility lies. The QOLSYS is designed to work with their systems, and the 2GIG version is designed to work with the 2GIG systems. This information would have been helpful in the product description above, and now I see why so many people are returning them due to the lack of that little tidbit of information. Additionally the vendor charges a RESTOCKING fee for returns unlike so many other vendors on Amazon, so I almost wonder if the reason they don't mention the incompatibility issue is so they can make money restocking these units over and over when people return them.