Each Süka heater has its own individual electronic thermostatic control unit. This is situated on the left side panel of the radiator with a control dial showing a frost guard symbol and numbers 1 to 8. This number range covers the complete change of temperature that occurs throughout our climate. The heater also has a sensor unit at the bottom which measures ambient temperature and airflow at floor level. The simplicity of this type of controller is that the programming has already been done for you.