Very plugged condensate line, need expert help.

[MarriedinOrlando]

So our upstairs master air handler backed up and flooded the downstairs roof. That's the easy part.

Now I've had 2 contractors in and neither can fix this. The 2nd contractor is recommending a positive pressure pump given the distance and inability to clear the line.

We cleared it with wet vac and air tight attachment.
We cleared it with nitrogen.
We ran Triple D.
I have Liquid Plumber foaming inside it now....going nowhere.

But it's backed up right now again. He thinks that somewhere I have a sagging line and gravity is no longer working for us.

It's plumbed all weird with a P trap down about 2 feet over to an air line. That part makes sense. But the unit is interior to the home and the condensate must make at least 4 turns to the pad and ground trap because it comes up through the poured concrete pad.

Does it sound reasonable to put a positive pressure pump on this with fail safes I need anyways? I can add photos!

 

[MarriedinOrlando]

so the bypass I did so I could function. The hole on the left is where the condensate line went down. That's what you're looking at in the 2nd photo under the decking. There is an insulation over the p trap connecting the drip line on the left and air line on the right.....lots of turns for no damn reason in that condensate line. Poor installation.

 

[Sponsor]

 

[CountryBumkin]

So you cleared it once before, and now it's backup up again. What did you find clogging the line the first time (slime?)?
I think if it was just a sagging pipe you would still be able to "blow it out" with compressed air. Plus you have a lot of gravity working for you.
Perhaps something crawled up into the drain (mouse?) - even then I think you would be able to blow it out.
Where does the line exit, outside the house at grade?

 

[WorthFlorida]

On the outside of the home where the other end of the drain line is (you may have to cut the pipe), place a garden hose on it and back wash the system. Keep it on for maybe no more than 5 seconds and let the water drain back. If you can bring the hose upstairs and blow water into the pipe to flush it.
Most of the time it is slime buildup and even a shop vac can clean it out. As CountryBumkin stated there could be a mouse in the pipe. I say maybe a small snake or a good size gecko.
All air handlers need to have a safety switch installed. I had one or two back ups myself over the 25 years. There are two variants to connect the air handler. Then you wire it in series to the power lead (red wire) for the thermostat. When the water backs up the float switch opens the power and shuts the system down, therefore no more condensation. BTW... both of my boys were married in Orlando.

 

[JerryR]

I have Liquid Plumber foaming inside it now....going nowhere.

The Liquid Plumber complicates things a little due to it being corrosive alkaline.


1st step world be to put a wet vac on the line at the outdoor exit and pore water though the cap on the “air line” That cap is usually left unglued so you can remove it to pore water though it with the wet vac running to flush the line. I do this every 6 months and slowly pore about a gallon of water in the removed cap with the vac running to flush the line. I get lots of junk out.


2nd step would be to connect wet vac to the air line and try to reverse flush the clog in the line.


3rd step would be to remove the “drip line” from the Air handler and cap it off and suck out through the “air line”


Now that there is alkaline liquid Plumber in the line it makes it more complicated.


Last step would be to pressurize the line. If there is an unglued joint it may break free with pressure.


Look at my picture and you can see what Mr Worth is describing as the safety switch.