The control of condenser water temperature has undergone virtually no change since the advent of the water-to-air unitary heat pump. This paper shows the importance of optimizing condenser water temperature to maximize COP values throughout the year and discusses methods for accomplishing this through the use of available hardware. Though any water-cooled refrigeration system can benefit from condenser water temperature optimization, it is of particular value to systems such as the water-to-air unitary heat pump which operate year-round with some units in the cooling mode while others are in the heating mode.