Can anyone help me please. I had a Santon Premier plus fitted a while ago to over come the issue of pressure whilst running more than one shower. it has however failed to resolve the issue as when either another tap or shower is on the pressure drops. Is there something that needs to be done to the setting? There are two mains wires that come out of teh unit, one is attached to the wall, the other is wired to a plug but isn't plugged in does this impact things. Sorry i appreciate these are real base questions but i don't understand the system. You help would be greatly appreciated! thanks