Has anyone ever seen dual linesets on an a/c system before. Yes, thats right, two suction and two lines per condensing unit. Las summer we replaced several furnaces and a/c's at a friend's house and three of the units we replaced had dual linesets both 7/8 and 3/8. The units we replaced were a 2.5, 3, and 4 ton unit. The lines vary in length from 75 to 90 feet long and unfrotunatly the run 40 feet underground exposed to the soil. The units had been running fine all last summer and this summer until i noticed oil on the lines where they go into the ground. So we are going to have to figure out a way to run the lines through the garage into the basement now that we have a leak. When we did the install we replaced everything with Goodman. GSC13 condensors and GHM95 furnaces with TXV's and crankcase heaters on the a/c's. The old units were Magic Chefs but when we replaced the units, we decided to use only one liquid line instead of two -thought it would put too much strain on the compressors. Everything working fine until now since the house is 20 years old, but i was just wondering if anyone has ever run into this set up before.