You can tell by the sound of the vac machine if it's a clog -
- over-working, high pitch - as opposed to a broken line -
the sound would be normal, but no suction.


I can't tell what the sound means as the motor is in the garage and the
outlets are scattered about the house.



Both of the two central vac units that I have owned -
diffferent makes - had an additional inlet at the machine -
if yours does - you coulld check IT for suction - carry your
hose to the garage.. and listen to the motor..
Also - if IT doesn't have suction - ta-da.
John T.