I bought three sets of the Conrad FHT80B + Rad Valves, for 3 bedrooms.
The typical temp in each bedroom is approx 18 or 19 degress in the morning.
I am having problems with FHT80B temperature settings.
In order to get the valves to open at all, I have to set the FHT80B comfort temp at 22 degress or higher,
If I set the FHT80B comfort to 21 degresses or less, the valves remain permanently shut (displaying 0%).

Has anybody else encountered apparent Temperature inaccuracy of this scale (+3 or +4 degress inaccuracy)?
Any suggestions?