I just purchased (12/12/2010) a Rheem RGFE09EZCMS furnace with matching coil and condenser. After I removed the furnace from its cardboard container, I noticed a metallic rattle or jingling noise as I moved the furnace to where it will be installed. So I tapped on the exposed primary heat exchanger tubes with my finger, and determined that the heat exchanger is the source of the sound. It sounds as if a washer or a loose piece of metal is inside the tube or tubes. Also, if I lean the furnace forward, I hear something move and then produce a slight metallic clink when whatever is moving reaches its limit of movement. When I bring the furnace back to level and then tilt it backwards, I hear several metallic clinks as whatever it is moves in the opposite direction and stops. I am hesitant to install the furnace not knowing the source of the sound. I am sure that the vibration of the blower would also cause whatever it is to rattle, since only a slight tap with my finger can cause it. Are there baffles of some sort inside the heat exchanger tubes? I cannot find any diagrams of the heat exchanger with that level of detail. Has anyone encountered this? Thanks.