I have a new home with a WaterFurnace 3 ton Series 5 open loop system. The well pump is a 1.5 HP constant pressure set at about 120 ft. Since the house is not yet complete, I am running the system with NOTHING else drawing any power. I have the thermostat model that displays the power usage which includes the compressor as well as the fan. Yesterday when I left the house, I checked the readings on the thermostat as well as the power company's electric meter and then checked again today. As noted above, nothing else was left on (no lights or anything). Over the intervening 18.5 hour period, the thermostat reported 15.9 KWh consumption while the electric meter showed usage of 36 KWh. All of the compressor run time was in stage 1. This means that the well pump was apparently responsible for a little over 20 KWh of power consumption. The run time of the heating system during the 18.5 hour period was 10.5 hours. If the well pump was running at full capacity during the 10.5 hours, then it would have used a little under 12 KWh (1.5 HP x .746 KW/HP x 10.5 Hours). That leaves at least 8 KWh unaccounted for. If we assume that the well pump was pumping about 6 GPM as compared to full capacity of about 18 GPM, then the power used by the pump would be significantly less than the 12 KWh mentioned above and the power that I can't account for would be significantly greater than the 8 KWh figure. What am I missing here?