... Good intent, but ..

So how do I start ..
have my whole house or all radiators equipped with it .. this is now her 2 Winter.
Summary:
From 7 pieces in a short time 3 pcs started spinning. Drove from inexplicable reason to fully open.
In parts 2 pcs of items are defective.
Some have a wobbler, when setting set back to factory setting.
Example: in the bedroom had 2 pcs both radiator stand side by side, both thermostat are the same..
The A glowing and the other is from, or not at both heat (and in winter)

Pro: if you connect the things directly in the boiler room to the heating circuit, you have more of it