Abstract: A method for detecting the occurrence of snoring during operation of a machine configured for transporting liquid. The machine includes an impeller and an electric motor, operatively connected to a control unit. The method includes operating the machine in order to transport liquid on the condition that the instantaneous power of the machine is directed towards a set power level. The instantaneous power of the machine is allowed to fluctuate within a set power level range defined upwards by a max-factor times the set power level and defined downwards by a min-factor times the set power level. The method further includes determining the machine is snoring by the control unit when the instantaneous power of the machine is below a snoring level equal to a snoring-factor times the set power level by monitoring at least one of the operational parameters of power, current, or power factor of the machine.