I reviewed your other thread again. What still concerns me is the zone setup with bypass dampers, which will increase the return air temps and therefore increase the refrigerant pressure. This is definitely an issue. However, obviously your loopfield is too warm, too. Your delta T indicates that your flow is fine,so I am not sure the loop is airlocked.. WHAT kind of circulation pumps do you have? When you put a purge cart on it, you know immediately. When the water level in the drops more than 1-2" in the cart, you have air in the loop. There is also the possibility that your loop is not performing well due to dry sand. the combination of both would be killing your performance.