A method of operating a water-circulating household appliance, the water-circulating household appliance comprising an electric motor and a washing liquid circuit, the washing liquid circuit comprising a pump for circulating washing liquid through the washing liquid circuit, a portion of the washing liquid circuit being arranged in thermal communication with the electric motor, wherein the electric motor has a first direction of rotation and a second direction of rotation and is arranged to drive the pump, and wherein the pump has a primary direction of rotation corresponding to the first direction of rotation of the electric motor, and the method comprises a step of driving the electric motor, with a higher electrical power input than required for circulating the washing liquid through the washing liquid circuit with the pump rotating in the primary direction of rotation, characterised in that: the step of driving the electric motor is over a time period longer than 1 minute; and the step of driving the electric motor comprises a step of causing an excessive electrical loss in the electric motor exceeding a normal electrical loss in the electric motor associated with rotating the pump in the primary direction for circulating the washing liquid through the washing liquid circuit, wherein the step of causing the excessive electrical loss comprises a step of repeatedly starting and stopping the rotation of the electric motor a number of times during each of a number of consecutive 1 minute time periods; or wherein the step of causing an excessive electrical loss comprises a step of sending a DC voltage into at least one set of windings of the electric motor; or wherein the step of causing the excessive electrical loss comprises a step of sending an out of phase AC voltage through at least one set of windings of the electric motor. the step of driving the electric motor is over a time period longer than 1 minute; and the step of driving the electric motor comprises a step of causing an excessive electrical loss in the electric motor exceeding a normal electrical loss in the electric motor associated with rotating the pump in the primary direction for circulating the washing liquid through the washing liquid circuit, wherein the step of causing the excessive electrical loss comprises a step of repeatedly starting and stopping the rotation of the electric motor a number of times during each of a number of consecutive 1 minute time periods; or wherein the step of causing an excessive electrical loss comprises a step of sending a DC voltage into at least one set of windings of the electric motor; or wherein the step of causing the excessive electrical loss comprises a step of sending an out of phase AC voltage through at least one set of windings of the electric motor. wherein the step of causing the excessive electrical loss comprises a step of repeatedly starting and stopping the rotation of the electric motor a number of times during each of a number of consecutive 1 minute time periods; or wherein the step of causing an excessive electrical loss comprises a step of sending a DC voltage into at least one set of windings of the electric motor; or wherein the step of causing the excessive electrical loss comprises a step of sending an out of phase AC voltage through at least one set of windings of the electric motor.