"Ctal" wrote in message
oups.com...
We've got an attic AC unit. Over the past week the AC has shut down
(wonderful in our 90+ summer weather). It's doing this because of a
kill switch in the drip pan. As the drip pan fills up, it raises a
float on the switch and shuts the unit off.

From reading here, I believe the problem is caused by the primary drain
line being clogged? Can someone walk me through some steps to unclog
this line?

Shove something down the pipe until it is clear. Wire is good. A drain
snake may be OK but the tip may be too big. If that is the case, just cut
if off and run the flex portion down the tube. Most likely it is an
accumulation of dust the built up over time. Could be some slimey stuff
too, so once clear and flowing, pour a bleach solution in the pan and let it
drain.