Last May I installed a 5-ton Waterfurnace for my 3000 sq.ft. home with a pond loop. The pond is 6ft deep and 120'x60'. We live in southwest Michigan (hort. zone 6a). Cooling last summer was great, no problems at all. This winter is a disaster. The system goes into "fault" mode almost every day, sometimes more than once per day, and we can't get the temperature above 66 degrees. When the system is in the "fault" mode the compressor is turned off and the auxiliary electric heat runs by default. I shudder to think what my electric bill will be.
This autumn I got concerned about whether the system would heat enough in the winter and asked my dealer whether I should install a supplementary ground loop - he said no, we should be fine. I unfortunately did not know enough to turn the desuperheater off and I left a windmill-driven bubbler in the pond. The dealer's service man said that I should turn them both off (I did) but no improvement. He said that the coils are probably encased in ice and we may just have to wait until warmer weather melts the ice. Does this sound right? Is this system functioning correctly? Thanks