Just talked to another guy today about hot water baseboard heat and geothermal. Does it work? KINDA works. It will ‘probably’ work as long as it doesn’t get colder than 25 degrees out. Reason being is that baseboard radiant heat is designed around 160 / 180 degrees. Geothermal maxes out at 120 / 140 degrees. It’s the chink in its armor.
Now, to be fair… If you install twice or three times the fin tube required (off the cuff) to heat a house with 160 / 180 degree water you may be able to handle the homes heating load.
Not to say Geo may not be the way to go. Other options still exist. Can you install or do you have duct work? If so, install a forced air Geo system or a combination unit. In-floor radiant works great in conjuction with Geo. No matter the situation, if you are burning LP or Fuel oil, you will have a very respectable return, even IF you have to spend additional dollars to get the right system.