On Fri, 7 Apr 2017 20:32:53 GMT, "Tekkie®" wrote:

You could also use an electricians fish tape to find out where the
obstruction is.
My fish tape won't go around the elbows in the central vac pipe very
easily- not at all if one bend is 90 degrees to the previous bend.. I
find a 3/8" flexible air hose is about all that will easily traverse
multiple bends - and even that takes some patience.