AC Condensate Drain Clog - Impossible To Clear!

I recently noticed my primary AC Condensate drain was very clogged. In tracing it down with one of those pinhole waterproof cameras I found that its clogged for a good 7 feet in a section that goes from the attic to the master bathroom sink drain.

It is in a section that is not easy to blow with pressure or suck with a wet vac and I can't quite find the source of it because it seems to be somewhere near the sink drain in the master bath but my camera can't take the 90 degree turn from the wall to under the sink. From under the sink there are too many 90 degree turns for the camera to follow as well.

I have dried Drano into the access port - which I later read is probably really bad. I let it sit for a day and then tried vinegar which I later read is not as bad but may not be recommended. The drain does not seem fully clogged as it does allow some water through because during the day it does not overflow into the secondary drain until the end of the day. Presumably when the AC does not run as much at night it is able to catch up and when I check it first thing in the morning, the clog has usually gone down anywhere from 1-3 feet.

I have also tried getting it from the sink side with vinegar and baking soda through the sink drain.

Time to let a professional handle it or are there any other tips/tricks for this?

To give an idea of how the pipes are laid out, there is a primary drain for the AC condensate line with an access port about 1 foot away, it makes a 90 degree left turn from there and goes about 4 feet to another access port where it makes a 90 degree turn down the master bathroom's wall. It then makes a 90 degree turn under the sink with 2 more 90 degree turns to the drain which is just upstream of the p trap for the sink drain.

First time poster and recently just started getting involved in some home repair so do not hesitate to correct any of my terminology!

 

Did you try Drano liquid or the crystals? The crystals are much better & if you really want something strong, Liquid Fire from Ace is good. If the pipes aren't that old, it shouldn't damage them.

 

Thanks for the recommendation! I did the liquid and it was a fairly old bottle of it so it may have been expired and not very potent. The pipes are 17 years old so I would be concerned about anything much stronger but to be honest I don't know if that's "old" for that type of PVC pipe. I will have to give the crystals a shot.

 

For anyone curious, I had an AC guy over. I wanted him to check out some other areas of the system and was troubleshooting this in the meantime but he was able to clear it by blowing CO2 into the tube. I did not think that would easily work because of the placement and it was the second access port but he had me hold a towel over the openings in the sink and it pushed right through, terrible odors and all. I had just purchased the smalest diameter snake I could find too thinking I'd give that a shot but did not have to.

 

What did he use to blow the CO2 into the pipe? I wonder if that would work for grease in the kitchen sink drain?

 

He used something like this - https://www.grainger.com/product/1GDL7

It may but from what I have been reading, a plunger may be a better option for sinks due to the size of the pipe.

 

Thanks, it's a possibility.

 

Drain piping on HVAC equipment should always use threaded Tees and Crosses at turns, with the unused openings closed with threaded plugs or caps. This will allow opening the piping to run a rod, or better, a rod with a brush, through the piping. Use Teflon paste on the threaded caps or plugs and screw them in just slightly beyond hand tight.

 

For the most part this was the case but when it runs down into my sink, there are a few turns it has to take to make it to the drain trap and that's where the clog was. It didn't help that it was a 12-15ft run as well which is longer than most of the rods available and the turn is difficult for snakes but in the end a pump of some C02 saved the day.