update and question The contractor found the cause of the whine referred to in my earlier post. The first attempt was to install rubber dampers between the floor joists and the brackets supporting the circulating water pipes. This didn't correct the problem so today they cut out a small length (~18") of copper pipe running from the desuperheater to the water heater and another small length on the return pipe to the DSH and replaced the pieces removed with plastic pipe. Voila, problem solved! Apparently there was a resonance from the heat pump being transmitted throughout the house through the water pipes. My utility provides me, via the web, a daily update on my KWH usage. I now know that when we're away my base electric usage is ~10 KWH/day. When we're home, we consume an additional ~10-13 KWH/day. The Geo system, with the thermostat set at 76 and outdoor temperature ranging from the high 80s to the mid sixties uses ~20 KWH daily. For clarity, my usage totals ~ 40 KWH when we're home and the geo unit is running. My intention is to correlate this information with degree days and come up with some more definitive numbers. I now have a new question. I have a 12 KW generator to power my home when there is a power outage. The unit is connected to a transfer switch which automatically switches over to the generator when there is a power failure and feeds selected circuits in the house. The geo unit, of course, is one of the selected circuits. The auxiliary electric heat function of the WF unit is not a selected circuit since it requires more current than the generator can provide. Sounds simple, but it turns out that the geo unit will not run if the aux heat circuit is turned off. The contractor advises that a relay, energized when the generator powers up and runs, will need to be installed. The output from the relay (with the correct voltage) will then be connected directly to the thermostat, providing power to the thermostat without activating the aux heat. Sorry if I'm fuzzy here but that's how I understand the situation. I'm wondering if anyone here has encountered a similar situation and, if so, how did you handle it? Are there other options besides the relay? As always, all comments and suggestions are greatly appreciated.