I was gone for 6 weeks and came home and water dispenser would not dispense water. The water line was frozen near the lower left corner of the freezer door. I opened the door with the freezer off for about 10 minutes and the water line thawed, and water dispenses, but now there is a loud chattering sound from the rear of the frige. It lasts 20-30 seconds, then the water dispenses normally, but after a couple of minute wait, then the problem returns. Any help would be appreciated.