The tempature doesn't work. It is very cold every day because the different is 2 degrees.
I'm using Vaillant turboTEC pro boiler which was paired with Vaillant VRT 30 thermostat. When this thermostat came I had a problem with connecting it because old VRT30 thermostat used 3 wires and this particular thermostat had 4 connectors. After searching internet a while I found connecting schema (see pictures)