A machine for washing and thermodisinfecting sanitary items, comprising: - a wash tank with a drain duct extending downwards and comprising a siphon; - a reservoir, located higher than said wash tank, for the storage of hot or cold water which, during the wash and rinse phases, is sprayed by sprayers and/or nozzles present in said wash tank and fed by a pump which draws water from said reservoir; - a steam generator that injects steam into the wash tank through a steam pipe to achieve thermodisinfection; and - a controller that manages the operation of the machine's components based on its programming and the values detected by the machine's sensors; wherein the reservoir a) is connected to the wash tank by means of an upper conduit extending between the upper parts of said two elements, and a lower conduit extending between the lower parts of said two elements and provided with a shut-off valve; b) is connected to the external environment through a window in its upper part; c) is connected to said drain duct, upstream of its siphon, by means of a convection pipe the upper end of which is shaped as an inverted siphon, so that its end is facing downwards and is situated inside the reservoir at a lower elevation than the point where said convection pipe enters the upper part of the reservoir; d) is divided by a partial bulkhead, extending from its ceiling without reaching the bottom, into a condensation chamber into which said upper conduit enters and a convection chamber into which said convection pipe enters and said window is present, said partial bulkhead being provided with an opening which puts said two chambers of the reservoir into communication with each other and is situated at an elevation below said window and above the end of the convection pipe; e) is fitted in its condensation chamber with one or more nozzles fed by said pump and positioned to condense the steam entering through the upper conduit. - a wash tank with a drain duct extending downwards and comprising a siphon; - a reservoir, located higher than said wash tank, for the storage of hot or cold water which, during the wash and rinse phases, is sprayed by sprayers and/or nozzles present in said wash tank and fed by a pump which draws water from said reservoir; - a steam generator that injects steam into the wash tank through a steam pipe to achieve thermodisinfection; and - a controller that manages the operation of the machine's components based on its programming and the values detected by the machine's sensors; a) is connected to the wash tank by means of an upper conduit extending between the upper parts of said two elements, and a lower conduit extending between the lower parts of said two elements and provided with a shut-off valve; b) is connected to the external environment through a window in its upper part; c) is connected to said drain duct, upstream of its siphon, by means of a convection pipe the upper end of which is shaped as an inverted siphon, so that its end is facing downwards and is situated inside the reservoir at a lower elevation than the point where said convection pipe enters the upper part of the reservoir; d) is divided by a partial bulkhead, extending from its ceiling without reaching the bottom, into a condensation chamber into which said upper conduit enters and a convection chamber into which said convection pipe enters and said window is present, said partial bulkhead being provided with an opening which puts said two chambers of the reservoir into communication with each other and is situated at an elevation below said window and above the end of the convection pipe; e) is fitted in its condensation chamber with one or more nozzles fed by said pump and positioned to condense the steam entering through the upper conduit.