We are having a new system installed. The ground loops have been laid and were air pressurized to 55 on Friday. The contractor gave us the go ahead to backfill over the weekend. On Saturday, I checked the pressure, it was at 38. Could not reach the contractor. I decided not to backfill until I could talk to him. Now, on Sunday, pressure is down to 30. I lost a day yesterday, and likely another day today. My question to the forum is this: Is this air pressure loss normal, or do we likely have a leak? Should I continue backfilling or lose yet another weekend? Thanks for the input! (and no, still no return call from the contractor).