Return temp.
Push and hold the shift button to see:
- the calculated flow temperature
- the desired return temperature limitations.
This display can also show the actual and desired flow and return 
temperatures during DHW charging.
The activity of the motorized control valve is shown as arrows 
below the valve symbol. When the circulation pump is 
operating, it is indicated as ON below the pump symbol.
If a sensor is not mounted or is disconnected, the display will 
indicate it as “- -”.
If the sensor is short-circuited, the display will indicate 
it as  “- - -“.
If you are in doubt, remove the controller and check the 
ohmic value between the relevant terminals.
Relationship between temperature and ohmic value