Hi, I bought a 4500 sq ft house recently for a good deal (time will tell if it’s a good deal or not). I was excited to know that we had a geothermal system to heat and cooling the house, it’s a forced air. The previous landlord put in a 4 Ton water furnace system in the basement and a 2 Ton water furnace in the attic for the 2nd floor in 2001, it’s a ground loop, both units have their own loops that come from outside the house. They are R22 heat pumps. The 4 Ton in the basement has additional features - electric supplementary heating and hot water for radiant heat. I tracked the radiant tubings, it’s used for the kitchen floor and basement floor heating. Last month, the day after thanks giving, my 4 ton system gave up on me, I could smell some plastic burning but don’t know where it came from. Water furnace certified mechanic came home and tested the system and told me the system is grounded and compressor might be burnt out. we tried turning it on, the power immediately tripped at the main box. The system has two fuses on the main box, one is dedicated to the heat pump and water pumps and the other fuse is for electric heating. It’s currently running on electric to keep the house warm. To back it up we are using a wood stove to compensate ‘some heat’. I asked the mechanic how much it would cost to replace the system with 410a heat pump. He suggested to replace the entire system because the radiators might be contaminated and flushing is not easy. He gave me a $13K price for full install with no radiant heat option. I can’t afford $13K to get this going. I have decided to install by myself. I am a handy guy but will have to learn as I go as I have not worked on geothermal before but can quickly pick up know hows. I have attached the images of my current 4Ton system. The 2 Ton attic one is running fine but I am worried that it might fail eventually if it continues to be overloaded. Can someone please guide me in the right direction . ... should I replace the compressor from R22 to 410a or replace the entire system ? I looked up online, the entire system is costing between $ 4300 - $7000. And Compressor alone costs around $1500. Also can I use a 5 Ton system instead of 4 Ton one with hot water assist for radiant heat. I can’t find the specs that was used for the ground loop (closed system). Couldn’t find any excavation info for the ground loop install at the township office either. Does it really matter if I change my system from 4 Ton to a 5 or a 3.5 Ton system ?