I just finished my basement a couple of weeks ago and have been thinking
about installing a backup sump pump system. My current pump runs a few
times a day during the non-winter months and a few times/hour during a hard
rain storm. This type of sump pump activity is typical in my neighborhood,
where I suspect the water table is high. My next door neighbor had his
basement finished about six months ago. He had a water-powered backup sump
pump installed as he and his family are often away for entire weekends while
they stay at their summer cottage. Last Sunday night, he returned home and
his entire basement was flooded with about 8-12 inches of water. In
disbelief, he waded over to his sump pump and found water swirling around
and could hear water running through his backup system. He reached over and
shut off the water to the backup system and the swirling stopped ... he had
found the source of the flood water! Next he reached down into the sump pit
and jiggled the float on his primary pump. The primary pump came on and
immediately began pumping out the water. Within a few hours, there was no
more standing water in his basement, but needless to say, his new basement
was mostly destroyed. Luckily he was properly insured and his insurance is
taking care of the repair costs.
He called out his plumber that had installed the backup system. The plumber
mentioned something about debris being caught in a valve, which caused the
city water-fed backup system to be discharged into the sump pit! Since the
float on the main pump was apparently stuck, and the backup sump was
discharging city water into the basement, that explains how the basement got
so flooded. Unfortunately, my neighbor was at work while the plumber was at
his house and he couldn't personally verify what the plumber was telling
him, so we'll have to assume the plumber was correct and not just trying to
cover his a** for an improper installation.
I'm assuming the whole event got triggered due to the normal drain water
filling his sump pit, and when the main pump didn't pump out the water (due
to the stuck float), the backup system kicked in. But when it kicked in, it
apparently sucked up this debris which not only screwed up the backup
system's ability to pump the water out, but also began discharging city
water into the pit. I looked at his system this evening. Each pump had a
check valve installed between the pump and the common pipe used to deliver
the pumped water outside. The valve that the plumber claimed was full of
debris was down at the bottom of the backup pump's pipe. I couldn't see
very well down there, and given my limited knowledge of these systems, I
didn't really know what to look for. But I can't help wondering how this
"valve" which is supposed to suck water up out of the pit, can fail in such
a way that it can actually discharge water into the pit. This seems like a
major flaw with these types of systems if it's true. Is it true that they
can fail this way? If so, how does it happen? Is there a diagram of these
"valves" that show how they work?
Thanks in advance for any information.
They are very simple devices called Siphon Jets.
Here is one link of one along the lines of your friends:
ettfire.com/siphon_jet.html (you may need to cut and past to make it
It is the same as the way most good toilets work to flush. The basic
part has no moving parts and three openings, an inlet, an outlet and a
pressure inlet. The general idea is a wide pipe with a small nozzle inside
pointed towards the outlet which is fed by the high pressure water source.
When the pressure water is on, it sort of pulls additional water with it as
it exits out he outlet end.
They work well for low heads, I would wonder just how well they would
work trying to pump water out of a basement as for the pressure generally
available at home that would be difficult. I would guess it was the check
valve as indicated at the link that would have failed, and that is not
really part of the jet itself.
My guess is it might never work because it may not be able to develop
enough pressure to overcome the height of the basement wall. You will note
that the example in the link is powered by a fire truck. I have never seen
one working over more than a couple of feet.
This is one reason I put in a battery backed-up pump. Other reasons are:
1) I didn't have a convenient water line near the sump pit
2) The battery pump had much greater pumping capacity
3) Using water to eliminate water just seems like a bad idea to me -- your
story confirms that
My pump is supposed to have a 7-hour continuous reserve pumping capacity.
Even in the heaviest of storms, it only cycles once every few minutes -- so
I would suspect it could last several days without power. And even barring
that, I could always hook a car battery up to it to keep it going (assuming
I was home).
I use the Basement Watchdog, for what it's worth.
As in most things in life, YMMV. My water-powered emergency pump
saved me from having a pool in the finished basement during our recent
ice storm. All of my other neighbors ended up with several feet of
water in theirs, because their battery pumps couldn't keep up
for the 4 days the power was out. Now, everyone else has a
water pump. :-0
Personally, I can't imagine what sort of water-powered design would
allow the city water to enter the sump pit. I use the Zoeller
homeguard, and there simply isn't any way for the water to go anywhere
other than the storm sewer, short of the pipe breaking.
So, based on my experience, I would never, ever even consider
a battery-powered pump.
I, too, have a "Watchdog" as a second pump, and also have a generator
that I can run the AC pump. However, I really like the idea of the
water pump because, you really don't have to be present. I'm sure the
"Watchdog" can outpump the water pump in the short term. I guess if
there is room for all 3, that would be great.
You don't have to be present for the Watchdog either (just to clarify for
others who may see this and wonder). You'd only have to be present if the
battery ran down.
Watchdog pumps come in various capacities -- I got the 7-hour one (the
minimum) because we rarely lose power for long lengths of time, and our pump
rarely cycles faster than once every 5 minutes or so (and usually much less
than that). The 7 hours is for continuous pumping.
Everything has pro's and con's -- each individual needs to weigh them out.
Thanks for clarifying my original post ... that's what I meant. The
real problem is that a few years ago we had record rains in my immediate
area, about 17" in about 10 or 12 hours. At the peak, my AC pump was
running at about 80%. Of course I still had the capacity of the battery
pump, however, I know, if it were only the battery pump (we never lost
AC ... amazing!) it would NOT have kept up. I never expect to see that
much rain again in that short a period, but it can happen. I now have a
portable AC pump and hose that I could press into service in a few
minutes if necessary. Again, I have to be there.
Tim Fischer wrote:
I believe most of the will do ok during a simple power outage, but often
when the storms come the power goes out and the water comes in at the same
time, so the normal few minutes a day usage become much more than that.
What might be best really depends on your local situation.
as I have a few additional questions concerning the
Pumps are the norm where I live-- I compare it to a furnace-- sure your
house will flood if the pump is inoperable, just as it may freeze if the
furnace is inoperable. If there was a way to avoid having a pump (e.g.
building on higher ground or whatever) that might be preferable, but I don't
think having a pump is necessarily a Bad Thing (which sometimes folks
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.