In a dialysis machine having a water treatment module, a dialysate circuit circulating dialysate to a dialyzer, and an extracorporeal circuit having an arterial line and a venous line connected to said dialyzer transporting body fluids from a patient to said dialyzer and back to the patient, a method of disinfecting said water treatment module, dialysate circuit and extracorporeal circuit against bacteriological substances by circulating water through said water treatment module, dialysate circuit and extracorporeal circuit that has been heated to a high level disinfection temperature below the water's boiling point sufficient to achieve disinfection without the use of chemical cleaning agents, comprising the steps of:
- filtering water in said water treatment module through a reverse osmosis filter to produce filtered water;
- heating said filtered water within said dialysis machine to said high level disinfection temperature below the boiling point of said filtered water to produce heated, filtered water;
- placing said arterial and venous lines in fluid communication with said heated, filtered water;
- circulating said heated, filtered water through said water treatment module, dialysate circuit and extracorporeal circuit including said arterial line, venous line and dialyzer for a sufficient amount of time at or above said high level disinfection temperature to achieve disinfection of said water treatment module, dialysate circuit and extracorporeal circuit including said arterial and venous lines and said dialyzer.