In the same crock I have two sump pumps on two separate breakers. The
primary pump has a check valve installed and it drains into a underground
pipe that runs to a sewer. The backup pump float is set a little higher and
turns on if the primary doesn't. One and a half inch pvc pipe that rises
about 8 ft and does a 90 degree turn before heading outside and draining
onto the lawn and it has no check valve.
So here are the questions...Is there a valid reason for not having a check
valve on the backup? I had a failure on the primary pump and it seemed half
the crock was refilled by the remnants in the pipe draining back after the
backup pump shut off.
Is there a standard height a check valve should be installed and wouldn't it
make sense to install one on the backup pump?
This was the arrangement when we bought the house in March and I only
noticed this after the primary failed. Actually, the pump didn't fail, the
float switch did. $30 for a replacement.
I would think that if the water level get high enough to fill the
pump (as a result of the higher float switch), that a check valve
` The check balve is merely to keep the pump primed, and if the pump
is flooded, a check shouldn't be necessary unless it clicks on before
water level is high enough...... HOWEVER, that being said, what is
nature of the second sump pump.?? Is it a submersible, or is it a
that is mounted above the water level ?? That would be a problem....
I would use a check valve....
I will read with interest the advice given here by others. Lots
info to be gleanded from this group...
Andy in Eureka, Texas P.E.
Sump pumps are all self-priming out of necessity. And
a check valve will not keep it primed anyway. The water
between the pump and the valve drains back into the
sump pit. The valve is there to keept the rest of the water,
which could be substantial depending on how the piping
is run, from draining back into the pit. If it does, the pump
is just re-pumping that same amount of water that drains
back each cycle.
and if the pump
How many sump pumps have you seen that are mounted
above the water level? Every single one I've ever seen
sits in the sump pump pit, in the water.
That would be a problem....
None. But , based on the post, I wasn't sure the OP was referring
to a "sump pump", or a "pump that was used to pump out a sump".
People in different areas sometimes have different terminologies..
JoeJ replied that they were both submersible, hence, I can't see why
a check valve would be needed for either....
I agree with your post...but I can't see why you replied to "me"
than Joe J...
Andy in Eureka, Texas PE
Still trying to stay on topic. Both are submersible, primary has a check
valve that prevents the water from draining back into the crock. Backup has
no check valve and has at least 12 feet of 1.5" PVC before it reaches
outside. When that pump turns off, the contents of that 1.5" pipe drain
back into the crock and almost refill it. Yes it is just a backup and in
theory only runs if the primary fails, but in this case the primary did fail
and it didn't seem very economical to have it pumping the same water twice.
So, spend X dollars and install a check valve? I'll do it myself.
That's kind of a given, the pumps I've installed have a slope on the
output line after the check valve which I install in an area that's
less likely to freeze. I'm in the Southeast and temps don't usually
fall so low that basement temps get down to freezing. If I was in the
North, I'm sure I'd have to be more cautious installing any sort of
drain line. We Southerners are sissies when it comes to cold weather. I
worked out in the Pacific for a year close to The Equator so I lived
and worked in shorts and a T shirt every day. When I came back to The
States I landed in Southern California during a cold snap where temps
fell into the 60's and I was freezing. ^_^
Joe, I'm sorry, but I really don't understand.. If both pumps are
submersible, --- by that I mean the type that, when operational, is
partially submerged in the sump, I don't see the need for a check
valve in either.... As long as the float switches are above the pump
levels, the pump will be flooded.. and primed.... Water flowing back
down a discharge pipe will flow out to the ambient water level, which,
if the pump is still submerged, shouldn't matter.....
However, if your "primary" pump didn't work, you should get it
fixed.... As a suggestion, the problem may actually be in the
float switch (sold at Home Depot as a separate item for about $30
and is easy to replace..... generally.... The float switch fails more
than the pump does, in my experience....... which may not be as
great on this issue as other posters..
I like the idea of a backup..... especially if a small flood will
cause you serious difficulty or loss... But I'd have both systems
working ..... That's just me, tho....And I really like the "separate
Andy in Eureka, Texas
Maybe I'm not being clear. I replaced the float on the primary and I'm back
to having two operational pumps. A primary and a backup that kicks in if
the primary should fail. Both are submersible. If the primary fails and
the secondary needs to run, the water in the pipe seems to drain back down
and refill a portion of the crock because there is no check valve to prevent
the water from draining back down.
My original question was if there was a valid reason for not having a
check-valve in that pipe. From the answers, it doesn't appear to be any
reason to not have one and I can buy one for $10 and install it myself.
Several commenters don't have a clue. Yes, you should put a check
valve in the backup system since there is a lot of water stored in the
vertical pipe above the pump that you don't want to have running back
into the sump, when the pump is called upon in a failure of the first
pump. IT has nothing to do with priming or foot valves or anything
except what you originally surmised. The horizontal output pipe
should be sloped downward going out so that all water in the
horizontal pipe does drain out after the pump stops, especially if you
are in an area with freezing temperatures.
The only purpose of a check valve on a submersible pump is to prevent the
backflow which can cause the pump to cycle repeatedly.
The water in the pipe refills the basin prematurely. The pump kicks on,
shuts off and the whole process repeats again. Over time this can cause
premature pump failure. I once watched one with a small basin pump the same
water every 2 minutes. I added a check valve that very day.
For Joe: Add a check valve. Be sure to read the instructions. You need to
drill a 1/4" hole in the pipe near where it connects to the pump to allow
the water between the pump and the valve to drain.
Please come visit http://www.househomerepair.com
As Steve B stated, that 1/4" is unnecessary.
It's not like the internals of the pump will prevent that bit of water
between the pump and the check valve.
Drilling a hole in that location will allow a small amount of the
pumped water to "short circuit" and merely recycle in the sump,
wasting a bit of the pump's usable output.
General comment to group (not to Steve B):
I thought the "well" in which water collected was the "sump" and the
pump tasked with emptying the sump was the "sump pump"?
What is this "crock thing" being talked about?
I thought crocks were for sauerkraut, sourdough starter, pickles,
cheese, yogurt, etc and of course s...t.
It may not be necessary. But one thing I always do the first time I install
something is RTFM. Or at least look at the pictures.
Both the pump and the valve maker recommend the hole. I never throw
anything anyway so I have the printed instructions somewhere.
The Ace website indicates that their pump have a built in vent hole so it
may not be necessary for their product. Older pumps may not have the built
in hole. If you don't know for sure the small hole hurts nothing.
Please come visit http://www.househomerepair.com
I think you are right for the wrong reason. The two pumps discharge
to separate lines so no check valve is needed. If the pumps went to a
common line, the check valve would be needed to prevent backflow into
the other line and back to the crock.
I've always had check valves on both pumps in my old house for some 37
years. Both pumps were submersible and one was battery operated. The
only problem I had was with the battery pump. Sometimes, the head of
water would keep the battery pump from actually pumping, even though it
was running. The instructions on the Basement Watchdog battery pump say
to drill a small hole in the pipe just above where it connects to the
pump. I did it, and it worked. The best sump system is what I have now
... gravity. All perimeter tiles are just going to the side of the
mountain. If, for some reason, water should get in the basement (a walk
out on one side) just open the door.
That's a good point. If Joe adds a check valve, he should
put a small hole in the pipe too. Without a check valve, as
water rises in the pit, it will naturally rise inside the discharge
line as well, pushing air slowly out the discharge line. With
a check valve, the air is blocked, so you could have the portion
of the discharge line from the check valve down to the pump
itself filled with air. When the pump starts, it's possible the
line will remain air-locked. With the tiny hole the discharge
line will have water in it to the same level as the pit.
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