Servicing regime for a disposable set of a medical fluid therapy machine

A medical fluid delivery system comprising:

• a medical fluid delivery machine operating with a disposable set over multiple treatments to mix for each treatment at least one concentrate with purified water to form a medical fluid;
• a sensor configured to measure a conductivity of the medical fluid mixed by the medical fluid delivery machine, the sensor producing a mixing conductivity output;
• and
• a computer programmed to analyze the mixing conductivity output provided by the sensor to determine whether the disposable set needs to be replaced (i) immediately or (ii) for a treatment in the future by:
• determining an accuracy percentage of a commanded conductivity using the mixing conductivity output;
• comparing the accuracy percentage of the commanded conductivity to a soft limit;
• and
• determining the disposable set needs to be replaced when the accuracy percentage of the commanded conductivity is less than or equal to the soft limit.