An integral heat exchanger of water heater with heat pump is prepared as setting a lining at internal wall of inner container on water box, forming refrigerant channel between said lining and said inner container, connecting two ends of refrigerant channel separately to refrigerant inlet and outlet, forming said lining of water box by metal plate with excellent heat conductive property and shaping said metal plate to be cylindrical form with groove then connecting said lining to inner container of water box. |