Here is all that is listed in the manual that I have for the non plus version:
Push and hold CAL for 2 seconds until CO is displayed. You can now adjust the pointer to match the wind direction with the rocker switch at the bottom right of the instrument.
Push and hold CAL for 2 seconds to store.
To select windspeed units;
Push and hold CAL for 5 seconds until U1 or U2 is displayed;
Push CAL within 8 seconds to change units between meters / second and knots / second.
That is all it has.
If you are showing only F1, something may wrong with your wind head.