A dispenser of cooled or heated liquid which in one embodiment is a server cart for an aircraft. To avoid the need for a pump, the reservoir has a cooling or heating heat exchanger that helically coils around the main reservoir, which cools from the top down or heats from the bottom up, forming a counter current. The reservoir is connected to at least two conduits, one near the cooler top of the reservoir and one near the relatively warmer bottom of the reservoir. The two conduits connect to one another at a distance from the reservoir forming a dispensing passage, thereby allowing fluid to constantly circulate through the dispensing passage due to difference in the specific gravity in the fluid caused by the temperature difference. The elimination of the pump device is especially desirable for weight sensitive environments such as an aircraft.