aqua tronic w8500?

i have had a aqua tronic w8500 for about 1 year +, the problem that i am expericencing that when i turn the shower on there is no water coming out of the shower head but it is pouring straight down into the bath from an outlet from the box (behind where the shower hose connects to the shower).

but what i am finding is that when the shower is lowered into the bath the water starts to come out the shower head as well as the outlet... i am not mad!!!



please help!!!