A system, configured to be disposed in a information technology equipment rack for providing ice thermal storage, includes a tank configured to hold water, a heat exchanger disposed in water in the tank and configured to convey a two-phase liquid and vapor refrigerant and to transfer heat between the water and the refrigerant, a first valve connected to a liquid and a vapor refrigerant line and configured to selectively connect the liquid refrigerant line to a first port and the vapor refrigerant line to a second port in a first mode and to connect the liquid refrigerant line to the second port and the vapor refrigerant line to the first port in a second mode, a thermostatic expansion valve connected to an inlet of the heat exchanger, and a liquid/vapor pump connected to an outlet of the heat exchanger and to the second port of the first valve.