I have a Carrier forced air furnace with central air conditioning that was installed in 2001. This morning when I got up I noticed a really strange rattling/clicking noise on the lower level of the house. At first I thought it was just a register rattling, however, when I went down to the basement to check things out it was obvious that this noise is coming from the blower unit. I turned of the air and left the blower running and the noise is still there, so I'm pretty sure the problem is with the blower and not the a/c unit. After scouring several message boards I am at a loss as to what this might be. The noise is not a squealing noise which would indicate a belt and it is not a grinding noise which would indicate the motor. I have called a service technician, however, being a woman I like to have some sort of idea as to what the problem might be so that I don't get sold a bill of goods on an unnecessary repair. Any thoughts on what this might be? :confused:

Possible the fan is loose on the motor shaft.