The geothermal unit in my house is dead for lack of a better term. It is an 22 year old Waterfurnace 5 ton R22 unit with a leaking coil. Rather than fix it, I feel it is time for a replacement. I replaced the ECM fan motor last year and the compressor is obsolete. I am getting quotes for different units now going from 10-17k depending on quality on the unit. I happened to stumble on a Climatemaster Triology 45 unit that is almost exactly what I need for 10-20% of the cost of an installed unit. The unit was in a house being built and someone tried to steal it until they realized how heavy it was, the insurance company totaled out the unit because it was moved and now the fellow has to dispose if it. He stated there are only minor scratches to the unit with no other damage. The unit seems to meet me specs, 5 ton, right hand return, internal flow center, 20kw resistance heat. So my question. Is a DIY self install of a geothermal system doable/practical? To me it doesn't look too complex. Disconnect power lines, disconnect the loop lines, disconnect the desuperheater, disconnect the return and supply vents, remove the old unit and reinstall the new one. The three areas I am unsure about is 1) how to adapt from the old flow center to internal Climate master unit. Basically how do you adapt HDPE pipe and put an extension to the i/o of the inti itself. Is there a barbed compression fitting or similar that I can use instead of need a HDPE fuser? 2) I don't have the tools (flush carts) to purge/flush the coolant in the loop.Short of spending 2k on a fluch cart are there any ways for a homeowner to overcome this hurdle? 3) once installed how I don't have the tools to knowledge to flow balance the unit. Am I just dreaming too big that a homeowner could do a DYI replacement of a a geothermal unit themselves? I am almost certain I would not be supported with warranty service or parts form Climatemaster, however if I get the unit for 10-20% and spend another 10-20% on parts/help, I could walk away with a 60-80% savings. This all is a gamble. Thoughts?