System of detecting a leak in a heat exchanger of a hemodialysis device

A system comprising:

• a hemodialysis device including:
• a heat exchanger;
• a spent dialysate circuit including a drain valve and one or more sensors for measuring a fluid pressure in the spent dialysate circuit;
• and
• a fresh water circuit including a water inlet valve, the fresh water circuit being in fluid communication with the heat exchanger;
• and
• a controller connected to the hemodialysis device and executing a program stored in a memory to:
• selectively open and close the drain valve;
• selectively open and close the water inlet valve;
• determine, from the one or more sensors, a first measure of the fluid pressure via opening the drain valve and subsequently closing the drain valve after a pre-selected time period;
• determine, from the one or more sensors, additional measures of the fluid pressure at periodic time intervals;
• and
• determine whether the heat exchanger has a leak by one or more of comparing the first measure of the fluid pressure to a predetermined maximum fluid pressure value, comparing the additional measures of the fluid pressure to the predetermined maximum fluid pressure value, and comparing the first measure of the fluid pressure subtracted from each of the additional measures of the fluid pressure to a predetermined minimum fluid pressure differential value.