David,

I've been having the same problem with mine, except the ground post is intact. I went through 3 houses with open ground readings. The day I called Ideal to arrange replacement, it started working normally again. I think my problem is within the pigtail.

It's getting frustrating. This is the third unit heading for replacement in a little under 2 years. Honestly, I'm beginning to lose confidence in these analyzers.

Jeff