Apparatus comprising: a signal processor or processing module configured at least to: receive signaling containing information about motor speed and power data for a hydronic pumping system; and determine system pumping flow rate and pressure associated with an equivalent hydronic system characteristic variable using a 3-dimensional sensorless model or algorithm, based on the signaling received, wherein the signal processor or processing module is configured to implement the 3-dimensional sensorless model or algorithm based on processing signaling related to corresponding 3D reconstructed distribution functions of motor power, pump flow rate and pump differential pressure with respect to speed and equivalent system characteristic variable of C v represented by equation nos. 2.1, 2.2 and 2.3, as follows: w W n C v = 0, g Q n C v = 0, p P n C v = 0, where w, g and p are functions of the motor power of W, the system flow rate of Q and the pump differential pressure of P with respect to the motor speed and the equivalent system characteristic variable of C v, wherein the signal processor or processing module is configured to implement the 3-dimensional sensorless model or algorithm based on processing and obtaining, for a pair of given W and n motor readouts at an instant time, signaling related to unknown equivalent system characteristics variable of C v, in equation no. 2.1, and wherein the signal processor or processing module is configured to implement the 3-dimensional sensorless model or algorithm based on processing and obtaining signaling related to the pump differential pressure of P and flow rate of Q directly from equation nos. 3.1 and 3.2, as follows: g Q, n, w ^ W n = 0, p P, n, w ^ W n = 0, where ŵ is an inversely remapped power function of w. receive signaling containing information about motor speed and power data for a hydronic pumping system; and determine system pumping flow rate and pressure associated with an equivalent hydronic system characteristic variable using a 3-dimensional sensorless model or algorithm, based on the signaling received, wherein the signal processor or processing module is configured to implement the 3-dimensional sensorless model or algorithm based on processing signaling related to corresponding 3D reconstructed distribution functions of motor power, pump flow rate and pump differential pressure with respect to speed and equivalent system characteristic variable of C v represented by equation nos. 2.1, 2.2 and 2.3, as follows: w W n C v = 0, g Q n C v = 0, p P n C v = 0, where w, g and p are functions of the motor power of W, the system flow rate of Q and the pump differential pressure of P with respect to the motor speed and the equivalent system characteristic variable of C v, wherein the signal processor or processing module is configured to implement the 3-dimensional sensorless model or algorithm based on processing and obtaining, for a pair of given W and n motor readouts at an instant time, signaling related to unknown equivalent system characteristics variable of C v, in equation no. 2.1, and wherein the signal processor or processing module is configured to implement the 3-dimensional sensorless model or algorithm based on processing and obtaining signaling related to the pump differential pressure of P and flow rate of Q directly from equation nos. 3.1 and 3.2, as follows: g Q, n, w ^ W n = 0, p P, n, w ^ W n = 0, where ŵ is an inversely remapped power function of w.