Abstract: The invention is a 4 pipe geothermal heatpump heater/chiller device. It includes modular elements each having controllers on every module. A master controller may determine how many modules need to be in heating or cooling mode. The controlling of the modules and the switched four pipe arrangement would allow for any number of the modules to be running alternately in either heating or cooling mode at the same time. In between each module would be a spacer having isolation valves on the input and output side of the load side of each module. The valves would open and close depending on however many modules were desired to be in heating and or cooling mode, respectively. It may be also that a module is redundant, which can then be switched back and forth from either heating and or cooling mode, while the other modules themselves are left in their respective modes.