Purchase at 54 euros, to replace a Hysen that arrived defective (would not connect to WiFi). I decided to buy this type of thermostat (with transmitter and receiver) because the previous thermostat was in the wrong position and the room temperature was not being regulated properly. My problem was solved 100%, and now I can also control it via WiFi. The old one was a simple digital thermostat that used 2 AA batteries, whereas this one requires AC power from a socket or junction box. I plugged it into a socket nearby, but at some point, I will tidy it up a bit with a channel and white cable so it doesn't look so bad. You definitely need to consider the power supply in advance.
The receiver is a simple white box with some indicator LEDs. It has a main on/off switch, as well as a pairing button with the receiver that you will need to press once both are connected to power. There is a corresponding menu on the transmitter. Generally, while I easily connected them to power, WiFi, the burner, etc., they were not paired with each other, and it did not work immediately, even though the solution was just 3 seconds away. I assumed they would be paired from the factory (the Hysen was, for example). There should at least be an error indicator if not automatic pairing. Overall, the receiver is OK, I find it quite attractive, with modern discreet LEDs. They could have made it with type C and 18650 lithium batteries, for example, as I've seen similar devices like that. All Chinese, of course, but that's fine, the Hysen certainly had worse instructions and build quality. I didn't have trouble with installation, but I already had the cable ready that I had made for the Hysen, and an account on the "Smart Life" app. I think it also works with other similar apps if you want. You can also set a weekly schedule from the app, and some other parameters (temp correction, hysteresis temp, etc.). In the photo, you can also see a bit of the burner's wiring because for now, I'm using the holes from the old thermostat.
The transmitter is a very minimal device, like a small thermometer-clock. It shows room temperature, the temperature you've set for heating, and the time. It works with batteries or USB type C. No power adapter is included but I already had plenty. The screen is backlit, with white characters on a black background. It's quite good, definitely not perfect. It's clear where the lighting comes from, and from some angles, it's unreadable. Its base doesn't lock in any way, so with every movement (e.g., adjusting the temperature or dusting), the transmitter comes off the base. I didn't mount it on the wall, but it seems like a bad choice because you'll have to use it with batteries first, and second, to change batteries you need a screwdriver and to open some plastic clips. Apart from being tedious, the clips might break over time. The temperature setting is in 0.5-degree steps, with a rotary knob that feels nice. I'm really glad it doesn't have buttons or touch controls! If you press it inwards, it changes mode and with a long press, it enters the settings. You'll need this to sync it with the receiver. You can set when the radiator turns on/off to 0.5 degrees above/below the set temperature. I would have liked 0.3 as an option, maybe for those with a baby, for example.
Overall, it's a very good choice, especially for this money. In a month, it has never acted up, disconnected, frozen, or anything. I give it 4 stars because it has some drawbacks, but I don't know if you'll find anything better unless you spend a lot more money.