Just to clarify - the yellow lever under the bunk is the drain cock for the hot water held in the Alde boiler that will go to the taps. If a van is stored in winter it is a good idea to open this drain so that the hot water system does no freeze. With the lever (which is in a crazy place) is vertical the drain is open and horizontal when in use. So when you first connect up the system has to be filled from the aqualroll 15-20 litres and then the pump should shut off. I always fill with the kitchen tap open to shift the air and let you know when it is full. Turn the tap off and the pump should stop after a few seconds. When you turn the bathroom tap/shower after a fill you will get a bit of spitting whilst the air is cleared. Hope that helps.