Can anyone tell me how this until stores water, i have an Elddis Avante 2002, which i just took delivery of at the weekend, tonight was the first time i have tried the water system, i placed an aquaroll at the side with the water pump inside and turned on the tap and cold water came straight through to the tap, but if the water just comes straight to the tap the instructions say the water should go into the tank first which will take 10 litres once the tank is full then the water will come through the tap and i am not sure where to locate the switch for the electric water heater can someone help me.