I've had my GeoThermal system running for about a year now. I live in central North Carolina. It was installed in Dec 2013. It is a Bosch SM036 - 3 Ton - 2 Speed unit with 2 5k aux strips. The loop is a closed loop system with 1" pipe, 2 - 250 ft vertical wells in parallel and only water in the loops. Everything is 5 ft underground and comes into my crawl space under the footer and foundation, well below any freeze problems. The pipe is also completely insulated from the ground to the unit and back (pump in between). Last year, it ran perfectly and when the temps hit 9 deg it only needed to run stage 2 periodically to keep the house at 68 deg. This year, however, has not been smooth at all. Any time the temps drop into the 20's the unit will kick into stage 2 as normal when needed. However, after a while (5 to 15 min), the compressor will shut down. The aux strips kick in when the temps drop 2 degrees and I have strip heat from then until I shut the system off and back on. It then returns to normal, running mostly stage 1. The unit displays a freeze error. I had a tech from my contractor come out on a Sunday. He didn't have the right equipment with him but speculated that maybe my loop temps were hitting 30 deg. and the system was in protect mode. However, today around 4pm (around 34 deg outside), they were able to get back over here. We measured the temps of the loop. The input temp was 46.5 deg and the output temp was 40 deg when running at stage 2. I am now going to try to get it to fail tonight when the temps drop into the 20's again to see if the loop temps drop to 30 deg. 1) Does this much drop in temps for the loop seem reasonable? It would take the output of the unit to drop 10 deg from 40 this afternoon to 30 overnight. That seems like I would have a capacity issue with my loop if this occurs. 2). The loop installation is suspect to me. It is a parallel loop, however, both the first loops input and return are closest to the heat pump. The second loop is T'd off the first loop for both the input and the return. This means the water has to flow an extra 30 ft to the second loop and an extra 30 ft back. I would think the extra resistance would cause an uneven flow between the loops and a loss of capacity. Any thoughts on this would be more than welcome! Thanks.