For a long time I occasionally would smell sewer gas in the vicinity of my
kitchen sink. I thought it was because I hadn't been using my dishwasher. I
finally took a look under the sink and discovered that the discharge from
the dishwasher entered the drain downstream of the trap. So there was
nothing to prevent sewer gas from escaping from the dishwasher vent located
on the top of the sink. I revised the plumbing to correct this problem. In
one spot I had to use a coupler to connect two pieces of the drain and now I
have a slight leak at that joint. I've tightened the two nuts on either end
of the coupler as much as seemed safe to do but that didn't stop the leak.
What might be causing the leak and what could I do to correct it?

It would help to tell us what kind of pipe, plastic/metal, diameter, etc!!!

On Saturday, September 6, 2014 12:36:13 PM UTC-4, wrote:
It would help to tell us what kind of pipe, plastic/metal, diameter, etc!!!

If it uses a nut, they typically have plastic seals. New? Old?
Many times when they leak it's because the pipes aren't aligned
straight. Pipes need to line up, you can't rely on the fitting to
pull together pipes that are off on a slight angle. Also, you want
them to be hand tight, maybe a little more, as a starting point. If
it leaks, you can tighten a little more, but they aren't intended to
be made up real tight and oftern leak more if they are overtightened.

On Sat, 6 Sep 2014 09:43:51 -0700 (PDT), trader_4
wrote:

On Saturday, September 6, 2014 12:36:13 PM UTC-4, wrote:
It would help to tell us what kind of pipe, plastic/metal, diameter, etc!!!

If it uses a nut, they typically have plastic seals. New? Old?
Many times when they leak it's because the pipes aren't aligned
straight. Pipes need to line up, you can't rely on the fitting to
pull together pipes that are off on a slight angle. Also, you want
them to be hand tight, maybe a little more, as a starting point. If
it leaks, you can tighten a little more, but they aren't intended to
be made up real tight and oftern leak more if they are overtightened.

OP doesn't mention a garbage disposal. I'm thinking vibration on the
drain pipe.

wrote:
For a long time I occasionally would smell sewer gas in the vicinity of my
kitchen sink. I thought it was because I hadn't been using my dishwasher. I
finally took a look under the sink and discovered that the discharge from
the dishwasher entered the drain downstream of the trap.
Hi,
IMO, this is wrong.
DW installation manual mention this with drawings.
DW drain should be connected to above P trap using Y connector and you
don't need separate DW vent. If your DW vent is under the sink where the
sewer smell will go? I could be wrong but that's what I think.

So there was
nothing to prevent sewer gas from escaping from the dishwasher vent located
on the top of the sink. I revised the plumbing to correct this problem. In
one spot I had to use a coupler to connect two pieces of the drain and now I
have a slight leak at that joint. I've tightened the two nuts on either end
of the coupler as much as seemed safe to do but that didn't stop the leak.
What might be causing the leak and what could I do to correct it?

On Sat, 06 Sep 2014 13:43:26 -0600, Tony Hwang wrote:

wrote:
For a long time I occasionally would smell sewer gas in the vicinity of my
kitchen sink. I thought it was because I hadn't been using my dishwasher. I
finally took a look under the sink and discovered that the discharge from
the dishwasher entered the drain downstream of the trap.
Hi,
IMO, this is wrong.
DW installation manual mention this with drawings.
DW drain should be connected to above P trap using Y connector and you
don't need separate DW vent. If your DW vent is under the sink where the
sewer smell will go? I could be wrong but that's what I think.

So there was
nothing to prevent sewer gas from escaping from the dishwasher vent located
on the top of the sink. I revised the plumbing to correct this problem. In
one spot I had to use a coupler to connect two pieces of the drain and now I
have a slight leak at that joint. I've tightened the two nuts on either end
of the coupler as much as seemed safe to do but that didn't stop the leak.
What might be causing the leak and what could I do to correct it?

Sounds as if the dishwasher "vent" is in reality an air gap that some
jurisdictions require.
--
Mr.E

On Sat, 06 Sep 2014 16:22:14 -0400, Mr.E wrote:

Sounds as if the dishwasher "vent" is in reality an air gap that some
jurisdictions require.

I thought that. The air gap vent line is ordinarily attached to the
underside of the counter, with an arched loop. OP doesn't say if he
has a garbage disposal in the mix.

Pic:

http://www.fortworthinspector.com/sitebuilder/images/Air_gap2-646x335.jpg

https://tinyurl.com/nhl833v

OP is talking beyond the P-trap for the coupler leak.

On Saturday, September 6, 2014 3:43:26 PM UTC-4, Tony Hwang wrote:
wrote:

For a long time I occasionally would smell sewer gas in the vicinity of my

kitchen sink. I thought it was because I hadn't been using my dishwasher. I

finally took a look under the sink and discovered that the discharge from

the dishwasher entered the drain downstream of the trap.

Hi,

IMO, this is wrong.


I guess that's why he corrected it.



DW installation manual mention this with drawings.

DW drain should be connected to above P trap using Y connector and you

don't need separate DW vent. If your DW vent is under the sink where the

sewer smell will go? I could be wrong but that's what I think.


..