I have a Weather King AC/Furnace in the attic
I assume it is dripping water when the AC is running. If you look at the attic unit, there should be a PVC pipe running from the unit - probably an insulated PVC pipe. This pipe probably goes across the attic to the edge of the house and drains outside. The drain pan may also have a drain pipe, but the one on the AC unit is the issue, and is probably plugged. Go outside and see if you can locate the AC drain pipe. See if the ground is wet below the pipe and if water is steadily dripping from the pipe (with AC running). If the pipe and ground are dry, the pipe is plugged. If you have a wet/dry vac, try connecting it to the drain pipe outside to see if you can **** the pluggage out. If you can get it clear, water should start dripping out of the pipe. This same thing happened at our house. I decided to cut the pipe in the attic, and add in a PVC isolation valve, tee, and water hose connection with plug, so I can valve out the AC unit from the pipe, remove hose connection plug, and hook up a water hose and flush the line to outside. Lowe's sells all of the PVC pipe fittings. The water pressure from the hose will always flush out the algae and crud to the outside of the house. I can also remove the plug and pour a cup of bleach down the drain pipe every couple of months to keep algae growth in check. I also cut out the trap (u-leg) from pipe in the attic and purchased a ready made trap a Lowes (the contractor who built our house had made a lousy homemade trap). I purchased a few PVC elbows and installed the trap on the drain pipe outside. By the way, our AC drain pipe comes out of our wall outside and drains near our outside unit. Our secondary drain pan drain pipe comes out outside from an eave on the side of the house. I don't know what you drain line looks like (it may have a port to add bleach, or some cleanout provisions, maybe not). If you choose to modify/improve it, then make a sketch of it, go to Lowe's and get the PVC parts you need + PVC pipe primer and cement. PVC cement dries fast. Remember, the pipe must flow downhill from you AC attic unit. You can use a regular wood saw to cut the pipe. I hope this helps you. You need to keep the drain line clear as algae will continue to grow in it. Pouring bleach in the line every month or two helps. You also need to check maybe once a month that the line is draining properly (check to see if dripping outside). You can get some serious water damage to your ceilings if the water backs up and overflows. I discovered that our drain line was plugged just in time as our drain pan drain line was also partially plugged and drain pan was about to overflow.
