Ric, yes my system does "preheat" the water entering into my water heater. It does so in both winter and summer. I'm not sure how much of a difference it makes but a recent flyer sent from our power company said about 20% of an all electric home's power consumption is due to heating water. All the Geo systems I looked at had this feature built in ready for plumbing to the water heater.
"The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge." Stephen W. Hawking
