I poured bleach and vinegar, snaked from the outside, vacuum push and pull from inside and outside.
@fcabanski:
Most systems installed from early 80's on do not have the primary condensate line drain outside, but rather it goes into your home's plumbing. Usually, what you see dripping outside it is the overflow (emergency) pan, so if you are trying to clean from that PVC it won't do any good, as it is working properly. You have to access it from your evaporator coil in your attic, and you should see two separate PVC lines exiting. The higher up one is connected to your evaporator coil and is likely the plugged one. You can cut the PVC, install a PVC valve that you can close, and an access point (I did a small vertical riser) from which you can both see if it is flowing, close the upstream valve so no air can go upstream, and then use compressed air to blow down the line. If your system is older with only one line that goes outside to drain, then all my advice is useless. 4951