A heat pump for a dishwasher, comprising: a pump casing having a chamber defined with an inlet and an outlet; a motor connected with the pump casing and having a rotatable shaft extended into the chamber, the shaft defining an axial direction; an impeller disposed within the chamber and arranged on the rotatable shaft, which comprises a body part configured to pressurize fluid and an extending part having a diameter smaller than that of the body part, the extending part extending upwards in the axial direction toward the inlet and configured to receive fluid from the inlet; a heating assembly comprising a heating pipe disposed in the chamber, a fuse configured to protect the heating assembly, and a heater wire disposed in the heating pipe, wherein the heating pipe comprises an arc-shaped portion, a first linear portion and a second linear portion, the first linear portion and the second linear portion both extend in the axial direction, the arc-shaped portion defines a first end and a second end, the first linear portion defines an upper end and a lower end connected with the first end of the arc-shaped portion, and the second linear portion defines an upper end and a lower end connected with the second end of the arc-shaped portion, the upper ends of the first and second linear portions extend out of the pump casing, the fuse is disposed in at least one of the first and second linear portions and is remote from the arc-shaped portion, and the extending part is encircled by, spaced apart from and exposed to the arc-shaped portion; and a pressure switch assembly arranged on an outer wall of the pump casing, connected with the heating assembly and configured to protect the heating assembly. a pump casing having a chamber defined with an inlet and an outlet; a motor connected with the pump casing and having a rotatable shaft extended into the chamber, the shaft defining an axial direction; an impeller disposed within the chamber and arranged on the rotatable shaft, which comprises a body part configured to pressurize fluid and an extending part having a diameter smaller than that of the body part, the extending part extending upwards in the axial direction toward the inlet and configured to receive fluid from the inlet; a heating assembly comprising a heating pipe disposed in the chamber, a fuse configured to protect the heating assembly, and a heater wire disposed in the heating pipe, wherein the heating pipe comprises an arc-shaped portion, a first linear portion and a second linear portion, the first linear portion and the second linear portion both extend in the axial direction, the arc-shaped portion defines a first end and a second end, the first linear portion defines an upper end and a lower end connected with the first end of the arc-shaped portion, and the second linear portion defines an upper end and a lower end connected with the second end of the arc-shaped portion, the upper ends of the first and second linear portions extend out of the pump casing, the fuse is disposed in at least one of the first and second linear portions and is remote from the arc-shaped portion, and the extending part is encircled by, spaced apart from and exposed to the arc-shaped portion; and a pressure switch assembly arranged on an outer wall of the pump casing, connected with the heating assembly and configured to protect the heating assembly.