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? 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. 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.