Hi Atticus, EDTA's running out of range may be caused by a couple of things - My first question is: are the results repeatable? -- If so, a simple drift correction may set things right again.
Another thought is if they are continuing to increase in value it might take us to one of the reagents becoming depleted - in particular I would question the copper in the reduction tube or the CO2 and Moisture absorbers in the Aliquot Absorption tube.
If results are erratic and high it takes me after other maintenance such as cflex tubing replacement, ballast, doser maintenance....
If you have further questions LECO Technical Support may be reached by phone at 269-982-3247.