Hello, Clearly, you have a phase, a neutral and land on your installation. Ask a store clerk and ask him to see the technical manual of the device. The son that you think you too, may be the son of control for the heating management from a centralized controller
Good evening, I think Confusion between levels (6 levels) and son. The vast majority of radiators and towel dryers are equipped with electrical wire with three drivers. Blue for the neutral, a brown to a dark phase and for piloting. there is more green and yellow wire for grounding. The connection is made without problem area using only blue and brown. The black wire is not used and must be isolated if you do not have central control orders. In my opinion, if the facility has only one radiator, this Central is not helping. The central control determines the hours and periods of lay comfort, economy, Frost, stop heating, comfort -1 Â° and comfort-2 and is useful that from the two radiators in different rooms. FYI, I just installed a dry towel in a bathroom and two radiators are all connected and work perfectly without flight. You can buy your dry towel and install it without problem.