On Thu, 6 Apr 2017 03:51:45 -0000 (UTC), "Danny D."
wrote:

On Tue, 04 Apr 2017 08:56:43 -0400, opined:

Over about 30 years of using central vac in two homes -
I think that I've had maybe 3 or 4 clogs - all were in the hose -
not in the vac line. Just sayin' ...

The hose was snaked two years ago, right here, in a.h.r.
https://c4.staticflickr.com/8/7573/1...fb4ff8bd_c.jpg

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.

You might also hear the
location of the break inside the wall - it would noisy unless it was
a big open disconnection...

Hmmm. I may need to try that, but I never could figure out why it had such
low suction as it used to work just fine.

Maybe I should debug again.

If the hose is __definitely not__ the problem - check & snake the
inlet to the vac machine.

I have a 75-foot snake but what are the hoses made of inside the walls?
Are they strong enough to take a steel snake that is meant for plumbing?

I also have a 100 foot electricians snake.
But I'm afraid of puncturing the tubes inside the wall because I don't know
what they are made up of.
The tubes are generally polycarbonate or PVC. Just for giggles,
disconnect the pipe from the unit and check suction AT the unit. If
suction is good, you have a pipe issue. Reconnect the pipe and check
suction at the "service" outlet - on both of mine there is a place to
connect a hose directly to the unit. If you now have NO suction (or
very little) you have a leak, if you have good suction you likely have
a clog. If no suction at any of the outlets in the house, the clog is
close to the unit (shared pipe) - snake from the bottom. If you can
stick an air hose up the pipe and blast with pulses of air as you push
it up, you should be able to dislodge anything stuck in the pipe. A
3/8" air hose will snake around the tight ninety bends in the pipe. If
the clog is at a "WYE" in the pipe it is very likely the installer
installed it backwards, the air needs to follow the "sweep" of the
"T-Y" connector to prevent blockages.

Also, with the system running (turned on with the system switch) have
someone open the outlets one at a time and see how the motor pitch
changes.