On 6/9/2005 11:26 PM US(ET), Ed Hayes took fingers to keys, and typed
the following:

I have 2 zone central A/C in my home. I have forced hot air - A/C.
When the upstairs zone comes on, there is a buzzing noise downstairs
in the basement that vibrates up to the main floor.
The buzzing seems to be coming from the main duct.
It is not heard upstairs. (2nd floor)
It is not coming from the air handler in the basement or any of the
"what ever it is" that is in the attic.
Anyone have any ideas?
or
Should I call a service guy pronto?



If you have access to the ducts, you might look for a loose or
disconnected hanger strap. The unsupported duct might be resting against
a stud, joist, or other structural component.

--
Bill