Posted By engineer on 19 May 2011 11:27

An engineer practicing out-of-field may be worse than a complete tyro - the engineer knows just enough to be really dangerous...it's a bit like the difference between two and four wheel drive...in really tough going, having four wheel drive just causes one to get stuck further away from where help is available.

Sage advice here to be sure!
Eric

To get back to re some comments on water hardness. I found out that my water is 6gr per gallon hardness (calcium/magnesium), One part per million iron, and the "tds" is 50. These numbers come from a test done a few years ago by the guy who installed my water softener. I spoke with him today. He indicated that with an open loop system I would have to bypass the softener and run the water straight to the heat pumps, because the current softener does not have the capacity. Although he did qualify that he was by no means an expert, he thought that running water straight to the heat pumps may not be too big an issue because the calcium does not "harden" at low water temps. But....I don't know, the reddish "iron" stuff in my filters makes me think there would be an issue. There may be a way to filter that separately from the softener...but maybe not. Don't know if any of you all out there are familiar with that situation. I'm going to check with the manufacturer as stated above re what kind of water hardness the pumps can handle.

Thanks again to everybody for the tips and suggestions. It was very helpful for me.

The bigger problem for us with iron, is it likes to plug the drains downstream of heat pump and impede flow.
Easily remedied.
j