I have a dishwasher located in an area where there is no pre-existing
plumbing (ie - no sink nearby).

I've brought the water supply from the basement directly below the
dishwasher through a hole in the floor. I've routed the drain hose from
the pump directly down through the floor and connected it to a 2" ABS
drain pipe that runs at a slight down angle for about 10 feet and ties
into the existing drain system from the kitchen.

Normally I think that it's expected that the drain hose runs up above
the level of the drain pump for maybe a foot before it ties into a
nearby sink drain pipe.

But since I have my hose running down immediately when it comes off the
drain pump, I'm wondering if I might have some siphon action going on
whereby the water always has a tendency to drain through the pump even
if the pump isin't running - because I don't think that manufacturers
would install an electric cut-off valve to prevent water from draining
when it isin't supposed to.

Comments?

Sum Guy wrote:
I have a dishwasher located in an area where there is no pre-existing
plumbing (ie - no sink nearby).

I've brought the water supply from the basement directly below the
dishwasher through a hole in the floor. I've routed the drain hose from
the pump directly down through the floor and connected it to a 2" ABS
drain pipe that runs at a slight down angle for about 10 feet and ties
into the existing drain system from the kitchen.

Normally I think that it's expected that the drain hose runs up above
the level of the drain pump for maybe a foot before it ties into a
nearby sink drain pipe.

But since I have my hose running down immediately when it comes off the
drain pump, I'm wondering if I might have some siphon action going on
whereby the water always has a tendency to drain through the pump even
if the pump isin't running - because I don't think that manufacturers
would install an electric cut-off valve to prevent water from draining
when it isin't supposed to.

Comments?

How about using more drain hose and putting a big loop in the drain hose
so it rises before going thru the hole in the floor. Also might help
control sewer gas??

On Fri, 30 Jul 2010 21:03:54 -0400, Sum Guy wrote:

I have a dishwasher located in an area where there is no pre-existing
plumbing (ie - no sink nearby).

I've brought the water supply from the basement directly below the
dishwasher through a hole in the floor. I've routed the drain hose from
the pump directly down through the floor and connected it to a 2" ABS
drain pipe that runs at a slight down angle for about 10 feet and ties
into the existing drain system from the kitchen.

Normally I think that it's expected that the drain hose runs up above
the level of the drain pump for maybe a foot before it ties into a
nearby sink drain pipe.

But since I have my hose running down immediately when it comes off the
drain pump, I'm wondering if I might have some siphon action going on
whereby the water always has a tendency to drain through the pump even
if the pump isin't running - because I don't think that manufacturers
would install an electric cut-off valve to prevent water from draining
when it isin't supposed to.

Comments?

Most dishwashers require the drain hose to loop to a level higher than
what the highest possible operating water level. Read your
installation manual for your dishwasher.

Some may require an air gap. Read your installation manual for your
dishwasher.

Some have maximum lengths for the drain hose. Read your installation
manual for your dishwasher.

You will find the answer to all of our questions in your installation
manual for your dishwasher.

Why do people ask questions to strangers that they themselves could
answer by doing a little reading?

Gordon Shumway wrote:

Why do people ask questions to strangers that they themselves could
answer by doing a little reading?

This is a 14 year-old dish washer. I don't think I have the manual any
more.

I thought I was asking a question that would apply to all dishwashers.

On Fri, 30 Jul 2010 22:13:29 -0400, Sum Guy wrote:

Gordon Shumway wrote:

Why do people ask questions to strangers that they themselves could
answer by doing a little reading?

This is a 14 year-old dish washer. I don't think I have the manual any
more.

I thought I was asking a question that would apply to all dishwashers.

Did you go to the manufacturers web site and see if an installation
manual was available for download?

My dishwasher uses gravity drain to the basement washtub. This was a
quick temp fix 14 years ago till we put in a new kitchen which never
occured. The dishwasher has been replaced twice over the years.

I have a drain loop as high as the top of the dishwasher top to
prevent siphoning t works fine

wrote:
My dishwasher uses gravity drain to the basement washtub. This was a
quick temp fix 14 years ago till we put in a new kitchen which never
occured. The dishwasher has been replaced twice over the years.

I have a drain loop as high as the top of the dishwasher top to
prevent siphoning t works fine

That's what I suggested:-))

On Jul 30, 9:22*pm, " wrote:
My dishwasher uses gravity drain to the basement washtub. This was a
quick temp fix 14 years ago till we put in a new kitchen which never
occured. The dishwasher has been replaced twice over the years.

I have a drain loop as high as the top of the dishwasher top to
prevent siphoning t works fine

==
Yep, way to go.
==

"Gordon Shumway" wrote in message
news
Why do people ask questions to strangers that they themselves could
answer by doing a little reading?

You do realize you just contradicted yourself. g

Why not? I get plenty of really good advice here. I don't take the advice
literally but I often get steered in the right direction. Also, the process
of writing the question out probably helps me more than the answers.

This is a sounding board. The problem you have is always a problem someone
here has already been through. Bouncing ideas here and elsewhere is
priceless.

Have faith in the common man and remember the choice is always up to you and
you won't go wrong. If it seems like a stupid idea, it probably is, and if
it seems like good advice run with it. :-)

On Jul 30, 6:03*pm, Sum Guy wrote:
I have a dishwasher located in an area where there is no pre-existing
plumbing (ie - no sink nearby).

I've brought the water supply from the basement directly below the
dishwasher through a hole in the floor. *I've routed the drain hose from
the pump directly down through the floor and connected it to a 2" ABS
drain pipe that runs at a slight down angle for about 10 feet and ties
into the existing drain system from the kitchen.

Normally I think that it's expected that the drain hose runs up above
the level of the drain pump for maybe a foot before it ties into a
nearby sink drain pipe.

But since I have my hose running down immediately when it comes off the
drain pump, I'm wondering if I might have some siphon action going on
whereby the water always has a tendency to drain through the pump even
if the pump isin't running - because I don't think that manufacturers
would install an electric cut-off valve to prevent water from draining
when it isin't supposed to.

Comments?

What might happen if the “the existing drain system from the kitchen”
gets plugged up. Is the sewage entering from a higher source going to
start backing-up into your dishwasher and onto the floor?An air-gap
prevents this from happening.

"Molly Brown" wrote

What might happen if the “the existing drain system from the kitchen”
gets plugged up. Is the sewage entering from a higher source going to
start backing-up into your dishwasher and onto the floor?An air-gap
prevents this from happening.


Air gap is code in some places. OTOH, I've not had one in either of my
houses, a total of 40+ years and never a problem.

On Fri, 30 Jul 2010 19:48:36 -0700 (PDT), Molly Brown
wrote:

On Jul 30, 6:03*pm, Sum Guy wrote:
I have a dishwasher located in an area where there is no pre-existing
plumbing (ie - no sink nearby).

I've brought the water supply from the basement directly below the
dishwasher through a hole in the floor. *I've routed the drain hose from
the pump directly down through the floor and connected it to a 2" ABS
drain pipe that runs at a slight down angle for about 10 feet and ties
into the existing drain system from the kitchen.

Normally I think that it's expected that the drain hose runs up above
the level of the drain pump for maybe a foot before it ties into a
nearby sink drain pipe.

But since I have my hose running down immediately when it comes off the
drain pump, I'm wondering if I might have some siphon action going on
whereby the water always has a tendency to drain through the pump even
if the pump isin't running - because I don't think that manufacturers
would install an electric cut-off valve to prevent water from draining
when it isin't supposed to.

Comments?

What might happen if the “the existing drain system from the kitchen”
gets plugged up. Is the sewage entering from a higher source going to
start backing-up into your dishwasher and onto the floor?An air-gap
prevents this from happening.

Does it really?

An air gap is meant to break the siphoning action by allowing air to
fill what would otherwise be a siphon.

But with his suggested design and your suggested clog, it's not a
matter of siphoning. The water from above, including toilet sewage,
would stop at the clog, then go up the dishwasher hose to the
anti-siphon**, then a little will squeeze out the anti-siphon hole and
the rest would continue its route to the dishwasher, work its way
through the pump blades and end up in the bottom of the dishwasher.

**And up any other pipes available also, like the one to the bathtub,
the shower, the sinks, if they connect before the clog.

The way to avoid this is to not have clogs. I've been here 27 years
and never come close to a clog, and I never had a clog anywhere else
I've lived either. Because I don't let anything unusual go down the
drain. But i"m not saying a conscientious person can't have a clog.
I just don't know how it could happen.

If it ever does happen, he'll have to run the dishwasher through a
couple cycles empty to clean it out. That's a lot easier than
cleaning up a dirty overflowed toilet. (but not much harder than
cleaning out the bathtub) If the mechanism permits, he can speed it
through the washing and rinsing part since it will all be mixed with
water already anyhow.

On Jul 30, 9:33*pm, mm wrote:
On Fri, 30 Jul 2010 19:48:36 -0700 (PDT), Molly Brown





wrote:
On Jul 30, 6:03*pm, Sum Guy wrote:
I have a dishwasher located in an area where there is no pre-existing
plumbing (ie - no sink nearby).

I've brought the water supply from the basement directly below the
dishwasher through a hole in the floor. *I've routed the drain hose from
the pump directly down through the floor and connected it to a 2" ABS
drain pipe that runs at a slight down angle for about 10 feet and ties
into the existing drain system from the kitchen.

Normally I think that it's expected that the drain hose runs up above
the level of the drain pump for maybe a foot before it ties into a
nearby sink drain pipe.

But since I have my hose running down immediately when it comes off the
drain pump, I'm wondering if I might have some siphon action going on
whereby the water always has a tendency to drain through the pump even
if the pump isin't running - because I don't think that manufacturers
would install an electric cut-off valve to prevent water from draining
when it isin't supposed to.

Comments?

What might happen if the “the existing drain system from the kitchen”
gets plugged up. Is the sewage entering from a higher source going to
start backing-up into your dishwasher and onto the floor?An air-gap
prevents this from happening.

Does it really?

An air gap is meant to break the siphoning action by allowing air to
fill what would otherwise be a siphon.

But with his suggested design and your suggested clog, it's not a
matter of siphoning. *The water from above, including toilet sewage,
would stop at the clog, then go up the dishwasher hose to the
anti-siphon**, then a little will squeeze out the anti-siphon hole and
the rest would continue its route to the dishwasher, work its way
through the pump blades and end up in the bottom of the dishwasher.

**And up any other pipes available also, like the one to the bathtub,
the shower, the sinks, if they connect before the clog.

The way to avoid this is to not have clogs. *I've been here 27 years
and never come close to a clog, and I never had a clog anywhere else
I've lived either. Because I don't let anything unusual go down the
drain. *But i"m not saying a conscientious person can't have a clog.
I just don't know how it could happen.

If it ever does happen, he'll have to run the dishwasher through a
couple cycles empty to clean it out. *That's a lot easier than
cleaning up a dirty overflowed toilet. *(but not much harder than
cleaning out the bathtub) * If the mechanism permits, he can speed it
through the washing and rinsing part since it will all be mixed with
water already anyhow.- Hide quoted text -

- Show quoted text -

I’ve personally seen a house in a very affluent neighborhood of
California where the sewage from the street backed into the first
floor and completely flooded it and believe it or not the first floor
was about five feet higher than the street outside. Apparently this
house was somehow last in the sewer line coming down from a very
slight slope that apparently didn’t have an outlet or house for more
than five feet of rise. I had to pop open a clean-out outside so that
at least the sewage ran into the yard instead of the house until the
city could come and snake out the street from the manhole. .

On Fri, 30 Jul 2010 21:03:54 -0400, Sum Guy wrote:



But since I have my hose running down immediately when it comes off the
drain pump, I'm wondering if I might have some siphon action going on
whereby the water always has a tendency to drain through the pump even
if the pump isin't running

Do you mean, While you are washing the dishes, the water will be
draining, since it won't require a pump to drain?**

So if the water is draining while you're washing, new water, not yet
heated by the dishwasher, will be added to replace the water that has
drained out, and sometimes the dishwasher may pause if the water level
gets too low, until it goes up again. But I sort of think the water
can't drain during the wash and rinse spraying cycles, because the
pump that handles the draining is redirected to handle the spraying.
What about pauses, like the filling stages? Would whatever directs
the water to either spray or drain keep it from draining during the
fill stages? I guess the answer might be found in hallerb's post, but
he has a full heigbt loop. So I"m still curious.

If this is what you mean, it's not really siphoning**, which refers to
going uphill on its way to going downhill. For example, siphoning
from a gas tank requires it to up the hose from the tank to the
outside, and then downhill after that. That it can do this is the
"mystery of siphoning".

But except for the footnote**, you're just talking about going
downhill. That's called draining. :-)

Even if you're talking about the toilet draining from upstairs getting
stopped by a clog and then going up into the dishwasher, I think
that's called water finding its own level. I wouldn't call it
siphoning. Although it took me a while to realize this. I was also
influenced by the anti-siphon thing on the sink.

**Or do you mean that there is a trap in a normal dishwasher and if
you drain down, it will siphon the water out of the trap. I don't
think it's called a trap or built like a trap , but even if not a
trap, some water is left inside the dishwasher all the time that the
pump doesn't normally expel. There is such water aiui, but it's not
needed to stop sewer gases normally, because the normal output of a
dishwasher is to the sink drain above the sink trap. So the sink trap
stops the sewer gases.

Is the drain you plan to connect to, is it above a later trap, or are
there no more traps before you get to the sewer? If there are no more
traps, yes I think it will drain the water from the dishwasher
(whether that is called a trap or not.) and the sewer gasses will come
out through the dishwasher. (In the other post, I was only arguing
some more about the term siphoning.

If you put in a loop, woudl that be sufficient? Doesn't there need to
be an anti-siphon device, or indeed it would siphon.

IIUC, if you put in a loop, the inside bottom surface of the hose
would only have to be as high as the water level when the machine has
finished its cycle, or at most the surface water level while it is
running, which isn't that much higher, but I think others said it had
to be higher yet or at least theirs was higher.


- because I don't think that manufacturers
would install an electric cut-off valve to prevent water from draining
when it isin't supposed to.

I doubt they would, and regardless of whether you still have a
problem, I'd be interested in knowing what would happen if the drain
goes straight down.

Comments?

Sum Guy wrote:
I have a dishwasher located in an area where there is no pre-existing
plumbing (ie - no sink nearby).

I've brought the water supply from the basement directly below the
dishwasher through a hole in the floor. I've routed the drain hose
from the pump directly down through the floor and connected it to a
2" ABS drain pipe that runs at a slight down angle for about 10 feet
and ties into the existing drain system from the kitchen.

Normally I think that it's expected that the drain hose runs up above
the level of the drain pump for maybe a foot before it ties into a
nearby sink drain pipe.

But since I have my hose running down immediately when it comes off
the drain pump, I'm wondering if I might have some siphon action
going on whereby the water always has a tendency to drain through the
pump even if the pump isin't running - because I don't think that
manufacturers would install an electric cut-off valve to prevent
water from draining when it isin't supposed to.


What happens when you try your configuration?

On Jul 31, 8:12*am, "HeyBub" wrote:
Sum Guy wrote:
I have a dishwasher located in an area where there is no pre-existing
plumbing (ie - no sink nearby).

I've brought the water supply from the basement directly below the
dishwasher through a hole in the floor. *I've routed the drain hose
from the pump directly down through the floor and connected it to a
2" ABS drain pipe that runs at a slight down angle for about 10 feet
and ties into the existing drain system from the kitchen.

Normally I think that it's expected that the drain hose runs up above
the level of the drain pump for maybe a foot before it ties into a
nearby sink drain pipe.

But since I have my hose running down immediately when it comes off
the drain pump, I'm wondering if I might have some siphon action
going on whereby the water always has a tendency to drain through the
pump even if the pump isin't running - because I don't think that
manufacturers would install an electric cut-off valve to prevent
water from draining when it isin't supposed to.

What happens when you try your configuration?- Hide quoted text -

- Show quoted text -


I would be first concerned about whether or not there is a trap. From
the description, it sounds like it's a direct connection to a sewer
pipe. If so, that;s a code violation and could allow sewer gases to
enter the dishwasher.

If you have a trap with a proper vent system per code, and the end of
the dishwasher hose goes into the trap like a washing machine hose
would, ie it's not sealed, then I don't think you have any problems.
If the sewer backs up, the water will come out where the hose enters
the system and not go up into the dishwasher above.

On Jul 31, 7:38*am, wrote:
On Jul 31, 8:12*am, "HeyBub" wrote:



Sum Guy wrote:
I have a dishwasher located in an area where there is no pre-existing
plumbing (ie - no sink nearby).

I've brought the water supply from the basement directly below the
dishwasher through a hole in the floor. *I've routed the drain hose
from the pump directly down through the floor and connected it to a
2" ABS drain pipe that runs at a slight down angle for about 10 feet
and ties into the existing drain system from the kitchen.

Normally I think that it's expected that the drain hose runs up above
the level of the drain pump for maybe a foot before it ties into a
nearby sink drain pipe.

But since I have my hose running down immediately when it comes off
the drain pump, I'm wondering if I might have some siphon action
going on whereby the water always has a tendency to drain through the
pump even if the pump isin't running - because I don't think that
manufacturers would install an electric cut-off valve to prevent
water from draining when it isin't supposed to.

What happens when you try your configuration?- Hide quoted text -

- Show quoted text -

I would be first concerned about whether or not there is a trap. *From
the description, it sounds like it's a direct connection to a sewer
pipe. * If so, that;s a code violation and could allow sewer gases to
enter the dishwasher.

If you have a trap with a proper vent system per code, and the end of
the dishwasher hose goes into the trap like a washing machine hose
would, ie it's not sealed, then I don't think you have any problems.
If the sewer backs up, the water will come out where the hose enters
the system and not go up into the dishwasher above.

==
If he continues to build it as he described, he will seriously
compromise the sanitation of the dishwasher AND of the sewage system.
Best he get some expert advice and most likely qualified plumber as
well.
==

Roy wrote:

I would be first concerned about whether or not there is a trap.
From the description, it sounds like it's a direct connection to
a sewer pipe. If so, that's a code violation and could allow
sewer gases to enter the dishwasher.

You are correct - there is no trap between the dish washer and the sewer
line the way I have it right now.

Although I've never smelled anything strange in the dish washer,
probably because there could always be some water sitting in the pump
acting like a barrier preventing a direct airway connection to the sewer
line. Or the pump's impeller is enough of a barrier to prevent airflow.

If the sewer backs up, the water will come out where the hose
enters the system and not go up into the dishwasher above.

I'm not afraid of a sewer backup. We have a separate storm-water sewer
system that's not tied into our sewer system, and we're sitting on a
higher elevation (relatively speaking) compared to other parts of the
city. We don't have sump pumps in our basements either.

If he continues to build it as he described, he will
seriously compromise the sanitation of the dishwasher
AND of the sewage system.

Hydraulically speaking, I'm not concerned about backflow from the sewer
to the dish washer.

But I am curious about your concern about comprimising the sanitation of
the sewage system. Could you explain that point a little more?

Best he get some expert advice and most likely qualified
plumber as well.

I can't believe that something as simple as whether or not a dishwasher
drain hose must always form a loop (inverted trap) wouldn't be more well
known if it was common knowledge.

For example:

http://lgknowledgebase.com/kb/index....y&EntryID=3072

Note that in every diagram, the peak of the hose rises to the highest
level as close to the top of the sink as possible.

I'm not sure what that do-hickey is in the last diagram - identified as
an "air gap" that seems to protrude above the counter top. That can't
be a desirable thing to have poking through your counter-top.

This video:

http://www.youtube.com/watch?v=S_0OWuFVLNw

explains how sink drain water can run back into the dishwasher.

In my case, I'm providing the dishwasher with it's own large 2" drain
pipe that connects directly to one of the main 4" vertical lines that
drains a bunch of fixtures from several rooms (probably about half the
house).

If that 4" line ever backed up to the level of the top of my basement
ceiling, then another foot higher it would reach the level of the bottom
of my dishwasher, then another 1/2 foot higher it would reach the level
of the bowl of my main-floor toilet, and then another 2 feet higher the
backup would start filling the kitchen sink.

So if I was ever worried about a sewer backup into the dishwasher, it
wouldn't take much more to backup my ground-floor toilet bowl (I don't
have a basement toilet or sink, but if I did, then they'd backup before
my dishwasher would). I do have a basement floor drain near my furnace
where my AC condensate drains, but I'm not sure if that's tied into the
storm sewer or sanitary sewer (probably sanitary sewer). So that would
most likely backup before anything else would - unless the backup was
caused by a plug in my main vertical 4" drain pipes.

On Jul 31, 8:55*am, Sum Guy wrote:
Roy wrote:
I would be first concerned about whether or not there is a trap.
From the description, it sounds like it's a direct connection to
a sewer pipe. *If so, that's a code violation and could allow
sewer gases to enter the dishwasher.

You are correct - there is no trap between the dish washer and the sewer
line the way I have it right now.

Although I've never smelled anything strange in the dish washer,
probably because there could always be some water sitting in the pump
acting like a barrier preventing a direct airway connection to the sewer
line. *Or the pump's impeller is enough of a barrier to prevent airflow..

If the sewer backs up, the water will come out where the hose
enters the system and not go up into the dishwasher above.

I'm not afraid of a sewer backup. *We have a separate storm-water sewer
system that's not tied into our sewer system, and we're sitting on a
higher elevation (relatively speaking) compared to other parts of the
city. *We don't have sump pumps in our basements either.

If he continues to build it as he described, he will
seriously compromise the sanitation of the dishwasher
AND of the sewage system.

Hydraulically speaking, I'm not concerned about backflow from the sewer
to the dish washer.

But I am curious about your concern about comprimising the sanitation of
the sewage system. *Could you explain that point a little more?

Best he get some expert advice and most likely qualified
plumber as well.

I can't believe that something as simple as whether or not a dishwasher
drain hose must always form a loop (inverted trap) wouldn't be more well
known if it was common knowledge.

For example:

http://lgknowledgebase.com/kb/index....y&EntryID=3072

Note that in every diagram, the peak of the hose rises to the highest
level as close to the top of the sink as possible.

I'm not sure what that do-hickey is in the last diagram - identified as
an "air gap" that seems to protrude above the counter top. *That can't
be a desirable thing to have poking through your counter-top.

This video:

http://www.youtube.com/watch?v=S_0OWuFVLNw

explains how sink drain water can run back into the dishwasher.

In my case, I'm providing the dishwasher with it's own large 2" drain
pipe that connects directly to one of the main 4" vertical lines that
drains a bunch of fixtures from several rooms (probably about half the
house).

If that 4" line ever backed up to the level of the top of my basement
ceiling, then another foot higher it would reach the level of the bottom
of my dishwasher, then another 1/2 foot higher it would reach the level
of the bowl of my main-floor toilet, and then another 2 feet higher the
backup would start filling the kitchen sink.

So if I was ever worried about a sewer backup into the dishwasher, it
wouldn't take much more to backup my ground-floor toilet bowl (I don't
have a basement toilet or sink, but if I did, then they'd backup before
my dishwasher would). *I do have a basement floor drain near my furnace
where my AC condensate drains, but I'm not sure if that's tied into the
storm sewer or sanitary sewer (probably sanitary sewer). *So that would
most likely backup before anything else would - unless the backup was
caused by a plug in my main vertical 4" drain pipes.

==
Please talk to a plumber...he/she will provide the information that
you need desperately. You are laboring under a load of miss-
information and guesswork.

==

On Sat, 31 Jul 2010 10:55:27 -0400, Sum Guy wrote:


For example:

http://lgknowledgebase.com/kb/index....y&EntryID=3072

Note that in every diagram, the peak of the hose rises to the highest
level as close to the top of the sink as possible.

In the drawing but the text says the minimum is 30 inches. I think in
practice the easy place to put the air gap is at the rear of the sink.

I'm not sure what that do-hickey is in the last diagram - identified as
an "air gap" that seems to protrude above the counter top. That can't
be a desirable thing to have poking through your counter-top.

Why not? I have one. It doesn't get in the way. The air gap is the
whole point of it. That's what stops the siphoning**. BTW, I once
had a little chicken bone, the one next to the drumstick, in the
air-vent and the dishwasher would not drain. It took a while to find
the problem, and I'm still not sure how this little bone kept it from
draining.

**although I'll admit, I havent' figured out when there would be
siphoning, or even in which direction. Stuff that would go into the
dishwasher woudn't be siphoned in, I think. Maybe it is there to stop
the water in the bottom of the dishwasher from being siphoned out????

This video:

http://www.youtube.com/watch?v=S_0OWuFVLNw

explains how sink drain water can run back into the dishwasher.

I'll have to look at that.

In my case, I'm providing the dishwasher with it's own large 2" drain
pipe that connects directly to one of the main 4" vertical lines that
drains a bunch of fixtures from several rooms (probably about half the
house).

If that 4" line ever backed up to the level of the top of my basement
ceiling, then another foot higher it would reach the level of the bottom
of my dishwasher, then another 1/2 foot higher it would reach the level
of the bowl of my main-floor toilet, and then another 2 feet higher the
backup would start filling the kitchen sink.

Yes, the toilet would overflow first if the backup was in the 4" line.

So if I was ever worried about a sewer backup into the dishwasher, it
wouldn't take much more to backup my ground-floor toilet bowl (I don't
have a basement toilet or sink, but if I did, then they'd backup before
my dishwasher would). I do have a basement floor drain near my furnace
where my AC condensate drains, but I'm not sure if that's tied into the
storm sewer or sanitary sewer (probably sanitary sewer). So that would
most likely backup before anything else would - unless the backup was
caused by a plug in my main vertical 4" drain pipes.

In article , (Sum Guy) writes:

[...]
| I can't believe that something as simple as whether or not a dishwasher
| drain hose must always form a loop (inverted trap) wouldn't be more well
| known if it was common knowledge.

One problem is that code requirements have changed over the years and
dishwasher (cost reduction) design has taken advantage of this. My
house's original dishwasher (~1959) was hard plumbed directly to a trap
in the basement. It had no high loop, no air gap, and no standpipe.
It did have a positive drain valve solenoid that closed the drain when
it was not trying to pump out water. It was also wider than current
dishwashers. As far as I know, that installation was to code at the time.

The first replacement dishwasher (in the 80's I think) was a KitchenAid
and while it did not have a drain valve it did use a separate pump for
removing water. It was happy with a high loop but still hard plumbed to
the trap in the basement. I _think_ the installation manual showed the
hard-piped trap as a valid (though not necessarily legal) configuration.

The next replacement (I don't remember the brand) in the 90's (notice
that life span is decreasing did not have a separate pump for removing
water. Instead it manipulated the circulating pump in such a way as to
cause a little plastic flap in a chamber to divert water out. This appeared
to depend critically on the back-pressure at the drain and I was unable to
make it work reliably with the hard-piped trap, regardless of high loops.

I was able to find a different brand that still worked with the hard-piped
trap, but I decided that that configuration's days were numbered so I
reworked the kitchen sink setup with a garbage disposal. The latest
replacement dishwasher has a high loop and empties into the dishwasher
port of that garbage disposal per the current preferred configuration.

IMHO, in general, a high loop saves you only if the drain hose opens
to air before it gets back as low as the highest water level in the
machine. This is the case with the garbage disposal port but not with
a hard-plumbed trap below the floor and not even with a standpipe below
the floor.

[...]
| I'm not sure what that do-hickey is in the last diagram - identified as
| an "air gap" that seems to protrude above the counter top. That can't
| be a desirable thing to have poking through your counter-top.

As the name implies, it is a true air gap that both prevents siphon and
diverts any reverse sewage flow onto your counter (which is arguably
better than hiding it in the dishwasher). The aperture on the dishwasher
side is smaller than that on the sewer side. This is currently the
ultimate in safety and (I believe) required by code in some places.
Something I'm not clear on is whether you can use an air gap and then
hard-plumb the outlet to a trap under the floor. Somehow I think that
even with the air gap you are supposed to enter a disposal or open sink
trap.

Dan Lanciani
ddl@danlan.*com

Sum Guy wrote:
I have a dishwasher located in an area where there is no pre-existing
plumbing (ie - no sink nearby).

I've brought the water supply from the basement directly below the
dishwasher through a hole in the floor. I've routed the drain hose from
the pump directly down through the floor and connected it to a 2" ABS
drain pipe that runs at a slight down angle for about 10 feet and ties
into the existing drain system from the kitchen.

Normally I think that it's expected that the drain hose runs up above
the level of the drain pump for maybe a foot before it ties into a
nearby sink drain pipe.

But since I have my hose running down immediately when it comes off the
drain pump, I'm wondering if I might have some siphon action going on
whereby the water always has a tendency to drain through the pump even
if the pump isin't running - because I don't think that manufacturers
would install an electric cut-off valve to prevent water from draining
when it isin't supposed to.

Comments?

As long as you are going at a continuous downward angle below the pump
it will siphon out just fine. It's when they drain into the sink drain
above the pump level that they need a loop above the drain level to get
siphon action to completely drain the dishwasher.




--
LSMFT

Those who would give up Essential Liberty
to purchase a little Temporary Safety,
deserve neither Liberty nor Safety.
Benjamin Franklin--

LSMFT wrote:

Comments?

As long as you are going at a continuous downward angle below the
pump it will siphon out just fine.

That's the problem. I'm wondering if the water is siphoning out when it
shouldn't be.

I can understand that the recommendation is that the drain hose make a
loop going up to above the level where the sink water-line might be - to
prevent the sink water from draining into the washer.

But if you don't have to worry about the drain from a sink (because
there isin't one nearby) then do you still have to worry about water
draining out of the washer when you don't have a rising loop in the
drain line?

"Sum Guy" wrote in message ...
I have a dishwasher located in an area where there is no pre-existing
plumbing (ie - no sink nearby).

I've brought the water supply from the basement directly below the
dishwasher through a hole in the floor. I've routed the drain hose from
the pump directly down through the floor and connected it to a 2" ABS
drain pipe that runs at a slight down angle for about 10 feet and ties
into the existing drain system from the kitchen.

Normally I think that it's expected that the drain hose runs up above
the level of the drain pump for maybe a foot before it ties into a
nearby sink drain pipe.

But since I have my hose running down immediately when it comes off the
drain pump, I'm wondering if I might have some siphon action going on
whereby the water always has a tendency to drain through the pump even
if the pump isin't running - because I don't think that manufacturers
would install an electric cut-off valve to prevent water from draining
when it isin't supposed to.

Comments?

Not sure I would make a direct connection to the drain in the basement. I
would probably add a stand pipe with trap and air vent much like I was
plumbing for a clothes washer. I would raise the drain to the dishwasher to
just below the countertop before heading to the basement simply because
every dishwasher install instructions that I've seen says to do it. Most
instructions allow increasing the hose length if needed.

Pat wrote:

Not sure I would make a direct connection to the drain in the
basement.

It's conveinent.

I would raise the drain to the dishwasher to just below the
countertop before heading to the basement simply because
every dishwasher install instructions that I've seen says
to do it.

(I don't have a countertop - this is a portable dishwasher that I've
parked in the corner of the kitchen).

Do they recommend it to prevent the sink from draining into the washer,
or because the washer needs the drain line to go up first before it's
connected to a drain pipe because it can't stop water from siphoning out
by itself.

On Jul 31, 4:13*pm, Sum Guy wrote:
Pat wrote:
Not sure I would make a direct connection to the drain in the
basement.

It's conveinent.

Your lights go out because a 15 amp fuse blows. Following your logic,
you put in a 30 amp one because it's convenient. The lights are back
on. Problem solved.

There is a reason why code requires a trap and vent on drains.
Several people here have tried to explain to you why what you're doing
can and likely will result in sewer gas entering the dishwasher and
living space. But that doesn't concern you.






I would raise the drain to the dishwasher to just below the
countertop before heading to the basement simply because
every dishwasher install instructions that I've seen says
to do it.

(I don't have a countertop - this is a portable dishwasher that I've
parked in the corner of the kitchen).

Do they recommend it to prevent the sink from draining into the washer,
or because the washer needs the drain line to go up first before it's
connected to a drain pipe because it can't stop water from siphoning out
by itself.

Going up first doesn't stop a siphon from working. I can place one
bucket of water 15 feet higher than another. Take a hose, fill it
with water, put it in the high bucket and let the hose rise another 2
feet above the bucket. Put the other end in the lower bucket. The
water will still siphon.

The high loop is there so that if the sink drain backs up, it will
rise into the sink first and will only get to the dishwasher if it
rises clear to the top of the high loop, ie as high as the bottom of
the counter top. For it to rise that high is quite unlikely and
someone will likely notice the backup, as opposed to it going unoticed
and just contaminating the dishwasher.

But, why all the concern? You obviously don't care about doing
plumbing to code when there is an obvious and very good reason for the
code, ie a trap and vent to prevent sewer gas from coming into the
house. The dishwasher seems to be working, so just do it your way.

wrote:

Do they recommend it to prevent the sink from draining into the
washer, or because the washer needs the drain line to go up
first before it's connected to a drain pipe because it can't
stop water from siphoning out by itself.

Going up first doesn't stop a siphon from working.

Replace the word "siphoning" with "draining" above.

The high loop is there so that if the sink drain backs up,

I don't have a sink drain. The dish washer is not competing with a sink
in this case. The washer is located in a corner of the kitchen away
from the kitchen counter and sink. The dish washer is not sharing a
common 2" drain pipe with an adjacent sink.

I've explained many times - I've arranged it so that the dish washer
discharge line is fed directly DOWN from the drain pump outlet through
the floor to a dedicated 2" ABS line that runs at a slight down-angle
for 10 feet to a connection on one of my primary 4" vertical sewer pipes
that runs into my concrete basement floor.

If something backs up on that 4" line, then I've got more of a problem
that could ever be solved by having a proper dedicated trap and vent for
the washer.

But, why all the concern?

Because my washer does not seem to be operating properly - it seems to
need to have water added at times during the various cleaning cycles as
if water is leaving it for some reason.

I'm wondering if the water is draining through the drain pump because
there is no "up-loop" in the discharge line.

But, why all the concern?

Because my washer does not seem to be operating properly - it seems to
need to have water added at times during the various cleaning cycles as
if water is leaving it for some reason.

I'm wondering if the water is draining through the drain pump because
there is no "up-loop" in the discharge line.

Likely. Also the sewer gases are coming up into your dishwasher and
entering your house 24/7. The dishwasher is made to vent the air/moisture
inside out into your house.

On Jul 31, 8:19*pm, Sum Guy wrote:
wrote:
Do they recommend it to prevent the sink from draining into the
washer, or because the washer needs the drain line to go up
first before it's connected to a drain pipe because it can't
stop water from siphoning out by itself.

Going up first doesn't stop a siphon from working.

Replace the word "siphoning" with "draining" above.

The high loop is there so that if the sink drain backs up,

I don't have a sink drain. *The dish washer is not competing with a sink
in this case. *The washer is located in a corner of the kitchen away
from the kitchen counter and sink. *The dish washer is not sharing a
common 2" drain pipe with an adjacent sink. *


No **** Sherlock, There was discussion about why the high loop was
called for in dishwasher installations. That was the point. It's
perfectly clear that you not only don't have a sink, but in fact are
connecting the dishwasher drain straight downhill into a sewer pipe
without a trap. I think just about everyone here will tell you:

A - That's a clear code violation

B - It's one code where the reason for it is clear and it makes
perfect sense.




I've explained many times - I've arranged it so that the dish washer
discharge line is fed directly DOWN from the drain pump outlet through
the floor to a dedicated 2" ABS line that runs at a slight down-angle
for 10 feet to a connection on one of my primary 4" vertical sewer pipes
that runs into my concrete basement floor.

If something backs up on that 4" line, then I've got more of a problem
that could ever be solved by having a proper dedicated trap and vent for
the washer.


Sigh... Once again, traps in sewer systems are not there to prevent
your sewer from backing up. They are there to prevent SEWER GASES
FROM ENTERING YOUR HOUSE every day. If traps aren't needed, why the
hell does every sink, washer, toilet, etc have one? You're concerned
that water may be running out of the dishwasher, but not that sewer
gas can be coming back in? Sounds great. Cleaned dishes sitting in
a closed dishwasher, exposed to sewer gas.




But, why all the concern?

Because my washer does not seem to be operating properly - it seems to
need to have water added at times during the various cleaning cycles as
if water is leaving it for some reason.

I'm wondering if the water is draining through the drain pump because
there is no "up-loop" in the discharge line.


If it's behaving that way, then it could very well be happening. Do
you think every dishwasher uses exactly the same pump out design? No
one here is gonna know how your dishwasher, which you don't even
indicate the make or model is going to behave when you use it in a way
MOST people never would. As others have suggested, you could go to
the manfacturer's website and see if you can find an owners manual.
But even that will probably not answer the question. They will show
how it should be installed, but likely won't tell you what happens if
you do it another way.

But instead of speculating, why don't you just put a high loop in it
temporarily and see if it then works correctly? And regardless, get a
trap and do it right.