Moen 920-004 Flo by Moen Smart Water Detector, 1-Pack

This alarm works perfectly at detecting water. A few caveats: As people mentioned, the pairing and Wi-Fi setup steps are missing from provided setup instructions, however, within minutes I located a short YouTube video that quickly filled in the blanks, and once you do this, it takes a few minutes to connect. Second caveat is that the provided alarm is very quiet. Your smartphone has louder ring options. So, you really need to rely upon the iPhone notification alerts to have a clue that it is going off, unless you are sleeping right next to your sump pump or wherever. I rigged mine to hang into a basement drain with the sensor on cord. Works. My sump failed, and I would never have known since I don’t go into basement daily and check, and dehumidifier regularly drains to this pump. I got a notification on iPhone from the Flo app while away from home, and checked sump upon return to determine sump had failed, but water was still in drain, so no overflow. I caught it early enough to minimize cleanup. It’s just a little, relatively cheap device, but it works.

I've been looking around for a battery operated water sensor, this one was a little on the pricey side. But the app was easy to use and setup. If you have a bandsteering unified wifi you might momentarily lose connection during setup if your phone is setup to use 5Gz, as this is a 2.4Ghz, the device will momentarily show disconnected during the setup phase, disconnect from your wifi and reconnect and you'll be fine, I had it up and running in 10 minutes. I dont know why people were complaining finding batteries for this, any of the big box stores have them. And if yours came with a dead battery return it for a new one.

I purchased 4 of these devices: The first 2 paired without issue and appear to be working fine. The battery on the first one died within a few days, and the 2nd one lasted about 2 weeks before dying. These use CRA123 batteries which do not come cheap. I was never able to pair the 3rd one, no matter what I tried; it always failed once I connected to the wifi network. I tried adding the network manually, I tried resetting the router, I tried changing the AP name, I tried manually connecting to the network, every single attempt failed, and customer service is of absolutely no use. The 4th one paired, and despite having a brand new battery (not the one provided) it reported the battery at 43%. I took out the battery, and the app never informed me that the device was offline, I even waited 20 minutes to see, and still nothing, it was reporting the same 43% battery level and offline. Bottom line: I would not trust these things to alert me in case of a water leak. Given the cost of each device, I would have expected it work flawlessly, but I'll be returning them and going with either Honeywell or pretty much any other brand. If your devices all appear to be working, I highly recommend doing a test to see if they are reporting correctly, dip the sensor in water, try taking out the battery, and see if the app reports it.

Doesn’t work, I tried to returned but need to send to USA and costs a lot. Not compatible with app

No instructions re setting up in box. Finally got it working after search youtube. Stopped working when wifi ( as a result of nbn outage) and haven’t been about to get it going since. Assuming battery supplied was depleted and can’t make any further suggestions until I purchase a battery - not a common one you have around the house so buy a few for future replacement