AN chillers and heat pumps have been designed and constructed to satisfy small and medium sized cooling and heating applications in residential or commercial applications. The machine is arranged for using both hydraulic circuits (evaporator and condensing unit), therefore it can be used both like water chiller and heat pump. The commutation between chiller and heat pump operation is obtained managing the chiller circuit. The units can be arranged to satisfy a wide range of system requirements: with base or with integrated pump and storage tank. Condensing units without evaporator are also available. The electric heaters of compressors are standard for chiller and heat pump models with refrigerant R407C.