Country Boy is right on the money, noise from the geo system is a big factor. I have a two year old 4-ton hydro-delta Mega tek closed loop system coiled in the bottom of my pond. The only problem I have encounterd was a bad board which was turning on my emergency heat instead of using the geo when it was first installed, after the tech discoverd the problem it worked great.It takes a little time understanding all the noises that are going on in the begining, and these noises do get amplified through your metal ductwork IF you have a forced air system and a large open basement. I took quite a few photos of them installing the coils in the pond, if anyone is interested I will post a few pics, I saved about four thousand bucks looping 900 feet in my pond, and I dont think my Bass are any the wiser.
