Deaner,
I really like my open loop waterfurnace. It is 13 years old and I have had no maintenance issues other than changing the air filter. I have very hard water, but I only soften the water that feeds my water heater. I do not believe that it is practical, or necessary to soften water used by the water furnace. When it is running, it uses 6 gpm to heat/ cool a 2000 sqft home. The water dumps into my pond, but in the summertime I loose more water to evaporation than the waterfurnace provides.
If you already have your own water well and pump, the open loop geothermal should not cost much more than a standard air cooled heat pump. (I paid an $800 premium to get the waterfurnance and installed the water lines myself). It paid off the first year.
These openloop geothermal units are so simple they should cost less than a standard heatpump system because there is no outside condensor system.
