We installed a Carrier ground heat pump in our upstate NY 1430 sq ft weekend home. 2 years ago (slinkly pit configuration). Contractor installed $15k worth of insulation; assured us this was all that was needed. Results have been dismal; $3000 a year electric bill and we have been freezing cold; have closed off half the house. We are there only on weekends! Contractor promised us $100/mo electric bills. Nothing but excuses from contractor (says add more insulation, although we added all the insulation recommended at time of install). Last winter system failing by Jan 15 and geothermal "froze"; no heat at all by March. Overall cost was $75k, $25k back from government. We are experienced professionals and never have been taken like this in our combined 110 years on the planet. We got references. We talked to local professionals. Do not retrofit your home for geothermal. Give to environmental charities and keep burning fossil fuel.