Abstract: An ice bank chiller comprises a reservoir, a vertically extending cooling coil adjacent to a side wall of the reservoir, and an agitation pump for agitating water contained in the reservoir, the agitation pump being arranged to cause substantial circulation of the reservoir water adjacent to ice on both the upper and lower regions of the cooling coil in order to promote an even thickness of ice on the cooling coil. The agitation pump comprises an impeller rotatable within a pump housing, the housing being provided with a plurality of circumferentially spaced-apart pump outlets, through which streams of water are directed towards the ice on the upper region of the cooling coil (2).