Economic differential thermostat for forced solar.
(at the time I write the cheapest)
It comes with 3 temperature sensors.
That's how many operating programs it has.
Basically, it has a default that will work even if you haven't read anything from the manual and 2 others with auxiliary heating sources.
When you have auxiliary heating sources apart from the solar, it can operate a resistance or another source for some time for protection against legionella - antilegionella function.
It has anti-freeze protection that you don't set anything, it simply activates automatically if any of its temperature sensors detects a temperature of 2 degrees Celsius and turns off the circulator when it raises the temperature to 5 with the circulation of water.
It doesn't have much but it does the job it needs to do.
Its little screen is quite large and nice, and when you press a button, a blue backlight activates.
The box is also nice but small, and when all the necessary connections were made inside, it was very difficult for me to close it.
There is a manual on the internet that you can easily find in Greek.
Be careful, the relays do not give 220 directly; they are simply dry contacts, so the electrician must connect the currents appropriately.
Satisfied but let's see how it performs over the years.
In the photos, I show it with backlight off and on and approximately how its menu looks, testing the thermostat and the operation of the circulator (P) for 30 seconds.