A refrigerant recovery unit is provided that can clear oil from an oil inject path in order to prepare the unit to switch over to a different kind of oil. The refrigerant recovery unit includes an oil inject circuit that receives an oil from the oil bottle into the refrigerant system. The refrigerant recovery circuit is coupled in fluid communication with the oil inject circuit. The refrigerant recovery circuit is operable to receive and transfer a fluid drawn through the oil inject circuit. A controller is operatively connected to the refrigerant recovery circuit and to the oil inject circuit so that as the fluid is drawn through the oil inject circuit a quantity of the oil in the oil inject circuit is removed.