On Aug 30, 6:24*pm, "John Keiser"
wrote:
2 HP is probably oversized for a 2 inch pipe, but since this is a new
problem, that isn't the issue.

Since this happened when you switched the pool vac to manual, I'd think air
leak in that valve.

Another possibility. The problem occured when trying to manually
vacuum the pool. There are a variety of ways to manually vacuum a
pool, but one of the most common is to attach the vacuum to one of the
skimmer suction lines. And to increase the vacuum, it's also common
to shut off some or all of the other suction lines. If this was done
and with a 2hp pump, it could create a lot of suction. The problem
could come if the pool was installed using flex PVC pipe as opposed to
rigid. Around here, NJ, it's common to use regular PVC at the pool
pad, then transition to the flex underground. Flex PVC has a much
lower rating for suction than it does for pressure. Meaning with too
much suction in can possibly collapse. Last year a friend had a
section of flex PVC that had collapsed and was leaking, but in that
case it appeared most likely it was due to being damaged when
backfilled. Still, it took 3 years to fail. We located it by using
an air compressor to pressurize the line and got lucky when water and
air started bubbling out of the ground at the leak. Got even luckier
when the bad section was not under the stamped concrete pool deck.

Also, now that I'm thinking about it, how is this thing plumbed? Is
there only one suction line at the pump? On my pool pad there are
three seperate lines appearing with valves, two for skimmers and one
for the bottom drain. Meaning at the eqpt pad I can select from the
various suction lines going to the pump, it's not just a single line.








To check for obstructions, if you have some suction, I've tied a nut [any
small object which will negotiate the bends] on a strong [you probably don't
want this to break] nylon line and let the pump suck it from the skimmer. If
you get through, there is probably no obstruction; or you can tie *a larger
nut on when it reaches the strainer and pull back through the skimmer.

"Lee" wrote in message

...



I realize this is not directly related to the purpose of this group,
so if you know of a better place for me to ask, please let me know.

We have a problem with our Pentair-WhisperFlo pool pump. *It is not
able to fully prime, even with addition of water into the pump body
directly (via the volute/strainer basket). *It seems able to draw
about 1/2 the amount it needs to fully prime and operate. *We have
replaced the pump impeller, and have tried to clear the inlet line (1
inch PVC pipe) through pressure from a garden-hose expansion nozzle
from both directions. *Nothing has worked. *We believe there is
probably a blockage/obstruction of some kind in the pipe between the
pool and the pump (perhaps a tree root that has gradually penetrated
the pipe).

Does anyone have any ideas of what else we can do to find out if there
is an obstruction in this inlet pipe? *Our resources are quite tight,
so hiring a plumber to come in with specialized/optical equipment
would be beyond our reach at this point.

Thanks for any suggestions you may have.

Lee- Hide quoted text -

- Show quoted text -