I tried out my new Zoeller non-automatic .3 hp sump pump, and the
instructions say to drill a 3/16 hole on the discharge pipe about
equal to the top of the machine. I did this, and not only does it
reduce the discharge pressure, but it makes an irritating spraying
sound when the water level drops below that point and the water sprays
against the side of the pit. Instructions say that this hole is
required to deal with air buildup when used in conjunction with a one-
way valve. Does anyone have an opinion on if the hole is really
On another note, I didn't know that the the pump I was replacing was .
5 hp, and it appears that the lower hp of my new pump results in a
dramatic drop in pressure. Interestingly, the old pump is actually an
automatic unit with a float switch, where they just taped up the
switch in an always-on position so that the on/off function is left to
the separate switch unit that the pump is plugged into. I didn't
discover this until I pulled out the old pump and found the float
switch taped to the discharge pipe.
> the hole is not needed.
What he said. I've installed two of those same pumps, and the people at
the plumbing supply store I bought them at said to ignore those
instructions. They work just fine without any extra holes.
Go ahead and plug the hole (find a screw and mash it in, or drill & tap
if you're a little more on the anal side; stainless screw for
"Wikipedia ... it reminds me ... of dogs barking idiotically through
endless nights. It is so bad that a sort of grandeur creeps into it.
I wouldn't be so quick to say that the hole is not needed with all
pumps under all circumstances. The small hole is there to prevent
air lock. With a check valve, if the sump goes dry, the section of
pipe between the pump and the check valve will fill with air.
Depending on the pump, this air could prevent the pump from picking up
enough water to get going. In essence the pump could remain air
locked and not pump while the basement floods. IF it happens depends
on the pump design, how deep in the water the pump sits, etc.
I;ve had pumps that did not have the air escape hole and worked
fine. But I'd read the pump directions and/or consult the
manufacturer and play it safe.
On Jul 18, 11:17 pm, email@example.com wrote:
Assuming that there is a check valve above the pump that does not leak
back _and_ that the pump totally empties the pump housing before
shutting off, yes, it could air lock even with the pit full of water.
There would be no way for water to push the air out of the pump
Of course you don't need REALLY need that hole; the pump manufacturer
was just being perverse -- you know, "goofing" you. Who REALLY needs
manufacturers instructions? Who's REALLY heard of Zoeller, anyway?
Try the following google search:
But, first, be sure to ask someone on alt.home.repair if you REALLY need
to do a web search. I'll bet you don't, REALLY.
BTW, just to keep the manufacturer's joke going, I drilled that little
hole and even check it out to be sure it's open. But, hey, that's just
my sense of humor. LOL.
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