Dialysis fluid heating systems

A dialysis fluid heating system comprising:

• a plurality of conductive tubes;
• first and second end caps located at first and second ends of the tubes, the first end cap including a dialysis fluid inlet, the second end cap including a dialysis fluid outlet, the end caps and the plurality of conductive tubes configured such that the dialysis fluid can flow from the fluid inlet of the first end cap, through at least one first tube of the plurality of conductive tubes to the second end cap, through at least one second tube of the plurality of conductive tubes back to the first end cap, and through at least one third tube of the plurality of conductive tubes back to the second end cap;
• a conductive wire wound around an outside of each of the plurality of conductive tubes along at least a portion of a length of the plurality of conductive tubes extending between the first and second end caps;
• and
• electronics configured to supply power to the conductive wire, the wire forming a primary coil of a transformer, the plurality of conductive tubes forming a secondary coil of the transformer.

A dialysis fluid heating system comprising:

• a tube;
• an end cap located at a first end of the tube, the end cap including a dialysis fluid inlet and a dialysis fluid outlet;
• a strip of twisted plastic or metal extending into the tube, the strip configured such that the dialysis fluid is urged to flow from the fluid inlet to a second end of the tube and back to the dialysis fluid outlet;
• a conductive wire wound around an outside of the tube along at least a portion of a length of the tube extending between the first end of the tube and the second end of the tube;
• and
• electronics configured to supply power to the conductive wire, the wire forming a primary coil of a transformer, at least one of the tube and the strip being conductive and forming a secondary coil of the transformer.