On 26 Feb 2007 17:05:55 -0800, wrote:

On Feb 26, 9:34 am, GaryO @ . wrote:
On 24 Feb 2007 14:06:35 -0800, wrote:
Absolutely no idea whatsoever.

Looking at your photo again, I think it may be the freon lines. There
looks to be insulation wrapped around them.

That could be it. A similar looking tube comes out of the roof and
attached to the condenser unit.

I don't know about your particular setup, but often there is a tray
under units mounted in an attic to catch any water which may overflow
the pan (perhaps due to a plugged drain line) and direct it safely
away.

That's what I think this is. The drain line was clogged once and kept
spilling water into my hallway from the tray.

If you get a flashlight stuck in the drain line and you are in for
even bigger problems!! :-(

There was one heartstopping moment when it got stuck. Fortunately I
got it out.
OK, try this. Install an automatic vent between the AC trap and the
sewer line. Here is a link to one (just the first one I googled up)
:http://www.idealtruevalue.com/servlet/the-55484/Detail They come in
different sizes, so select one appropriate to your pipe size.

Wait, I thought you said automatic vents were subject to failure?

They do sometimes fail and cause odor problems, but then you just
replace them. They're cheap. If it has a threaded fitting, you can
just screw the new one on. They are commonly used in places like
island sinks where it is not possible to run a standard vent line up
to the roof.

But
I'll give it a shot, considering it's 4.99 I could at least order it
in case I need to use it later.

I don't know if this one is the correct size for your piping. Better
to go to a hardware store or HomeDepot/Lowes and look at their
selection. You will also need to cut the existing pipe (hacksaw) and
glue in the "T" fitting. From the looks of all the existing
couplings, etc, I'd replace about half of it rather than try to adapt
to it - probably easier in the long run.

Unfortunately I can't tell if
clearing out the vent pipe fixed the problem, because coincidentally
one of the kitchen drain lines came loose and I can't run the kitchen
sink to see if the smell problem is fixed. If it's not I'll
definitely try the automatic vent.

Oops! Now you probably have an odor problem under the kitchen sink!

This is generally standard plumbing, unless it has been hacked up like
your AC drain lines. Again the hardware store has all the necessary
trap and drain lines for this along with the sealing gaskets -
typically a kit with everything in it. Cheap stuff and often easier
to replace it than to reuse the old.

....gary