Protherm Cheetah 23 MOV

Advantages: Easy installation. Not noisy. Does not require user intervention after configuration. Reliable enough. Many service settings for fans to do it yourself. Very easy to maintain.

Disadvantages: There is no service documentation in the box. In general, this is not necessary for the average user.
When buying, the seller misled me, saying that the contours of the boiler are completely independent, i.e. in the mode of heating the water heating is not turned off. In fact, the burner is still one and if someone washes for a long time, the heating cools at this time ...
There is a little lack of simultaneous indication of temperature and pressure in the system on the display. But this is a feature of the model.
An alternate power source is needed in case of a power outage.

Comment: I bought this boiler a little over a year ago. Like any other volatile boiler, after installing out of the box does not work quite correctly. Adjustment by minimum and maximum gas pressure is required, otherwise a contrast shower will be in the water heating mode :) Since they installed it themselves, having saved quite a lot of money * (and deliberately deprived of a guarantee, of course), I had to independently understand all the intricacies.
Let's just say, in the presence of an engineering mindset and direct hands, this boiler can be fully serviced. All the service bikes on the forums that it takes years of training, that the slightest change in settings will inevitably destroy your boiler is nothing more than directly imposing your services to get very good money in 20-30 minutes of your time.
Actually, it turns out that any person can make a U-shaped manometer, measure the gas pressure in the system and adjust the min and max pressure accordingly, and this is practically all that is needed. Well, even if necessary, you can adjust the maximum power of the boiler. EVERYTHING. This is done 1 time and forever.

Of the minor faults over the year, there were only 2 points in which the quality of the gas pipes and the hardness of our water were not the fault of the manufacturer. 1 time the mesh of the electronic valve of scale was hammered. In the 2nd - scum gathered in the water pump and he began to tap while working. Both are very easy to disassemble, clean and reassemble.

Another tip: in no case do not use pipes in the system that are smaller in diameter than the fittings on the boiler.

Buying generally satisfied.