On Feb 27, 10:40 am, GaryO @ . wrote:

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

Actually, as my AC problems gave me a deep awareness of the importance
of P-traps, I've been keeping it full by trickling a little water into
the left sink, of which the drain line is still intact.

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.

I bought a section of PVC pretty much identical to the part that came
off, then got some PVC cement and tried doing it myself. Worked at
first then when enough water was going through it it came out again.
I figure I probably should just bite the bullet and spend 100 bucks on
a plumber to be safe.