In the present study, a sensorless method is proposed to determine the operating point on pump curves in a BLDC-driven centrifugal pump, and certain functional implementations of the operating point are investigated. To develop a sensorless system, a calibration method is defined for the setup time. System variables such as head, flow, and power are determined at runtime based on the calibration data and the control algorithm of the BLDC motor. Thus, beneficial improvements are achieved for centrifugal pump systems, since only motor phase current sensors are required at runtime. These parameters are used to force the system into various modes such as ``minimum energy,'' ``maximum efficiency,'' or ``fastest,'' which could be selected by the user. The experimental results for an open-loop pump system setup as a part of the experiment are presented.