Excellent, it solves your hands!
You just need an electrician to connect it for you, so you should also consider this cost. Don't try to connect it to the panel by yourself if you don't know what you're doing very well.

It works properly. The application is definitely not one of the best out there. Unjustifiably expensive since you can make the exact same combination (smart switch and power relay) for half the price

Chinese thing that typically sticks, loses signal, doesn't respond to commands, etc... I bought it and regretted it, it's not that the device has a problem in general, it's just that the water heater stays on several times and if you don't notice it, it just consumes electricity...
It has done it to me several times to the point where I wanted to get rid of it. Look for another device from a better brand.

After one month of use. Everything is good. It opens and closes via mobile. You can set the maximum operating time in case you forget to turn it off. The application is not user-friendly. I don't know how long the device will last.

The function of it is very good, its application is very good too. It works perfectly with the Google mini. I highly recommend it

After 2 months of use, I am completely satisfied. It works perfectly through the application and also through Alexa, and it can be fully automated to open and close at the desired time

Very good product.
I have had it for three weeks and so far it works without any problems. Finally, I can program the times when the water heater will turn on and off without worrying about forgetting to turn it off.

Amazing solution! Easy installation (better than an electrician) and very user-friendly application. I have been using it for almost a week and it works perfectly.

I have already installed 2 and they both work perfectly. No noise or anything. The only "issue" is that if you set the timer and activate it, it will only close when the set time has passed. (unless you change all the programming settings on your phone).

Excellent set. You can buy them separately as well. I have never had any issues so far. Even after a power outage, it reconnected to the wifi relatively quickly.

Very good purchase!
It arrived very quickly and it works PERFECTLY.
Do not install it yourself unless you are an expert or have expertise!
I have already been using it for a month and it has not presented any problems.
Finally, whenever I needed technical assistance, it was immediate and informative.

Quite a good switch. It is very easy to use and with the application, you can do everything. The only downsides are that it does not have a base for the panel and you have to buy the Sonoff base, and that when you place it on the panel, it stays more inside than the facade and leaves gaps.

I have it since the beginning of the summer and it solved my problem. Now I can easily turn on my water heater from wherever I am. Excellent product.

Exactly what it describes. Definitely an electrician for installation and ready. Be careful to have space in the panel. I have had it for about a year and no complaints or unreliability. When it opens and closes, it makes noise, like the relay is falling, but you get used to it. If you also have a night mode, it is perfect through the application programming.

We have been using it for three weeks on a water heater without any malfunction, I highly recommend it, very easy installation

I bought it 3 months ago. It was installed by an electrician and until today it works and I use it. I give it 3 stars because it has a reliability issue. That is, sometimes it commands the water heater to operate without being scheduled by the set operating hours program. So, be careful. I closely monitor it now because I don't trust it. I believe the problem is in the app software and not in the switch itself. I hope it will be resolved in a future update.
14/9/21: Unacceptable. It turns on by itself and whenever it wants. The app that controls its operation is unreliable. I wouldn't buy it. I don't know if there is any other app that works with it.

I replaced a previous 15A Sonoff switch that burned out after 2 months with this one. This one can handle up to 25A. It works nicely. The installation and connection are easy.
Two things I noticed. Firstly, when it turns on or off, it makes a loud noise, like the relay is dropping - it can be a bit scary if you're close by.
Secondly, in the mobile application, it doesn't show the power consumption...(not that I care too much).
The good thing is that it has an automatic shutdown function after x minutes from the time you turn it on. Very convenient because you don't need to remember to turn it off. It always turns off by itself, for example, in 20 minutes.
We'll see about the lifespan...
I think it's a good purchase. It's worth the money.

Quite good and quite helpful. It's worth its money! Connects with solar power. It has very good programming.
The only downside is that setting it up with the application is very difficult. You will find it with many tries.

The device, perhaps the best on the market. The result is perfect. Finally, you don't have the stress of whether you closed the water heater and you have hot water whenever you want with just one tap on the app! The connection is very easy!