NOVELTY - The system has a water- to- water heat pump comprising multiple heat exchangers for controlling heat transfer from water drawn from an outside water source, where water is supplied to a hot water storage tank (16) and a cold water holding tank (15). The heat exchangers comprise a cold water heat exchanger (41) and a hot water heat exchanger (40), where water entering the cold water tank is cooled by the cold water heat exchanger and returned to the cold tank, water entering the hot water tank is supplied to the hot water heat exchanger, and the heated water is returned to the hot water tank.    USE - Geothermal heat pump water heater system for heating water for domestic use utilizing geothermal energy in resident and commercial establishments.    ADVANTAGE - The system maximizes efficiency for transfer of heat due to the inherent efficiency of water- to- water transfer. The system utilizes geothermal energy and saves energy cost. The utilization of geothermal technology provides a ubiquitous fuel source. The geothermal water heater with photovoltaic panels as part of a grid connected to a photovoltaic system can be powered in a cost effective manner than to install a separate solar thermal system for water heating. The system provides residents and commercial establishments in tropical and desert climates chilled cold water at 45- 50 degrees Fahrenheit for purposes of drinking and bathing. The system significantly increases solar performance by both decreasing the electric backup used and lowering the solar panel operating temperature. The system can be easily operated and installed in any domestic or commercial dwelling or establishment. The system can be installed in place of most natural gas water heaters due to the lower electric service requirement for the heat pump, which can operate on a standard 15 A- 120V circuit. The water to water heat exchange has greater efficiency. The water to water technology utilizes less electricity to heat water, produces less noise and requires less maintenance to operate. The consequence of utilizing air to water devices results in cooling of volume area surrounding the device.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a method for heating water utilizing geothermal energy.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a geothermal heat pump water heater system without solar assist showing heat pump, tanks and heat exchangers immersed into the tanks to transfer heat.    Cold water holding tank (15)    Hot water storage tank (16)    Cold water tank inlet (20)    Hot water heat exchanger (40)    Cold water heat exchanger (41)