I have an 18 year old US Power GSDX geothermal hvac system that has developed a leak right under the left sight glass where the steel is mated to the copper. The steel has corroded and expanded from the 0.5 OD to 0.85 OD and the freon sniffer got real excited as it came upon the site. I have to make a decision. My house is roughly 2,000 sq. ft. with R 21 walls and R 30 ceilings. I have a finished basement. 1,200 sq. ft. with R 7.5 Styrofoam Wallmate on 90% of the exterior wall. The house was built in 1993 with a verified Super-E rating. The current hvac system is 4 tons. It is primarily responsible for the 2,000 sq. ft. living space, but does have a return in the basement. I have a wood stove and a 90% efficient 50,000 btu gas furnace the basement. I like redundant systems. All exterior walls are 2X6 with full insulation, wrapped and foam board. All windows are dual pain argon filled. Is my ground loop 2,000 ft. copper, horizontal butterfly layout - 7 ft. in ground with 40 tons of crushed 1/4 stone surrounding it. The system used R-22. What are my options? Chuck everything and start with a new system? Is Earthlinked good? Who are the competitors? Thank you for any and all insight.