Upon receiving a call about a Kenmore refrigerator emitting a knocking noise, I began by inspecting the appliance. The noise was traced to the waterline, which was loose and causing the disturbance. I carefully secured the waterline, ensuring it was properly connected and free from any kinks or obstructions. This resolved the knocking sound, restoring the refrigerator to its normal, quiet operation. The customer was pleased with the quick and effective resolution of the issue.