How to toggle pump into positive head configuration??????

[gurus]

I came across to a job where the customer complaining that the shower and pump (salmander) has been newly installed by another plumber and giving troubles since it has been installed. When i check that it was working into negative head mode. but it is in the position of positive head.
How can I toggle the pump into positive head configuration?

 

[Axel]

"How to toggle pump into negative head
configuration
If the orange L.E.D. (P) light is on turn off power. Turn power
on and the pump will run. Then the pump will stop and the
orange L.E.D. (P) will go out and the green L.E.D. (N) will
come on. When the green L.E.D. (N) comes on turn off power,
then back on within 5 seconds. The pump will run for the
second time and stop on the orange L.E.D. (P) which will then
go out and the green L.E.D. (N) will flash off, on – then the
green L.E.D. (N) will stay on. "