"Ross Payne" wrote:

is loud enough to be heard in the next room (when the TV is off). At times,
it is louder than at other times with no pattern I can figure out. Sears
says this is normal, but I wonder whether it might indicate a problem. Any
thoughts? Thanks.

From the discussion on air compressors in this group, it sounds like it
is unloading the pressure off the compressor, so it doesn't have to
start under full load.

So I'd agree that it is normal, if annoying.