On Feb 3, 4:52 pm, Richard J Kinch wrote:
When I run the kitchen sink, and the AC kicks on, I get a bad smell
throughout the apartment. If I run the kitchen sink, and the AC is
off, I get the same smell, just much fainter. I put a cork in the
pipe where it enters the drain pan, and run the kitchen sink and AC,
and got no smell at all. So I'm guessing it's coming from the drain
line. It's of varying strength, and I don't know if it's sewer gas or
not, but it's definitely unpleasant.

Do you have a trap in the condensate line? Should be there. Otherwise
you're pushing air out through it (traps dust which promotes clogging) or
suctioning sewer gas in (yuk).


Yep, there's a trap, though not an especially large one. I posted a
pic of it at:
http://i9.photobucket.com/albums/a93...r/AC_drain.jpg

I'm trying to figure out if there's a way to somehow intentionally
empty the trap so I can see if the smell comes without having to run
the kitchen sink.

But while I can understand how pressure differences caused when the
kitchen sink runs could suck water out of the p-trap, I don't
understand:

a) how this connects to the condensate line, as I thought those were
separate from any line the kitchen sink would connect to, or
b) what exactly the smell is from, as absent a serious mold problem a
condensate line shouldn't smell like much of anything (as I understand
it).