Fully up = Off
1 Down = Auto
2 Down = Slow (always on)
3 Down = Fast (always on)
You can turn them off.
IIRC all you need to do is have them in the off position when turning the ignition on (without starting the engine).
I read about 30 topics on it recently because I was trying to get mine to turn ON!
On mine atm the 1 Down position doesn't do anything - I'm not sure if when the auto is deactivated they're meant do nothing (as mine do now) or go into a manual intermittent mode.