The removable 3 liter water tank sits in the rear of the machine with two hoses - one for the water intake and for the expansion relief valve which relieves excess water pressure by the powerful 52 watt pump. Important to minimize limescale build up, the Isomac Venus has an included water softener that should be recharged with regular table salt as least once a month. The brass boiler has three thermostats - coffee, steam, and safety. An item we never seen on a home model before is the stainless steel braided hose that goes from the pump output (top part) to the intake on the top of the boiler.