My unit most likely has a slow leak. It recently faulted out for a water flow fault. I am tired of calling the crappy company who installed the unit in 2006 so I ordered parts and re-filled with antifreeze and also loop conditioner. The unit ran for awhile and faulted out for water flow again. I am at 60 psi like the instructions on the conditioner said to be at, so I wonder if I have air in the system? Could it have gotten in because of the leak? It is possible that I introduced some when re-filling the system. Can somebody please tell me how to check for this and also how to remove the air if I find it? Thank you very much. Alan.