The Eaberspacher Easy Touch controller - When the room temperature is 3°C below the set-point temperature the HIGH fan speed will be automatically selected. When the ambient is 2°C below the set-point temperature the MEDIUM fan speed will be automatically selected. When the ambient is 1°C below the set-point temperature the LOW fan speed will be automatically selected. When set – point temperature is achieved the fan will switch off. If the temperature drops below set – point the fan will restart.
Please also see instruction manual weblink below
https://www.butlertechnik.com/downloads/cms/eberspacher-espar-easy-touch-operating-installation-instructions-manual.pdf