Central Air Unit Leaking Water

Hi all. I have a Carrier central air conditioning unit, which started leaking water the other day. I think I figured out where the leak is coming from, but don't know how to fix it. I'd appreciate any help/advice anyone can give me on how to fix this.

The leak seems to be coming from a small PVC pipe that goes from the furnace to the pipe that leads to the drain. I can move the pipe at the top enough to stick my finger in the pipe at the top, which is full of water. I'm guessing that the pipe is plugged somewhere along the pipe line. It's a long pipe that travels along the wall, behind a refrigerator, around a corner, then behind the washer and dryer. In other words, it's a long pipe that doesn't have easy access to most of it.

My guess would be, though, that the clog is in one of the traps, like the one just below where the water has collected or a slightly larger one that connects to the long straight pipe that leads to the drain. But even if that is the case, I still have no idea how to clean out the plug.

I've attached a picture of it. You will see all the towels I put under it to catch the water. The arrow is pointing to where water is backed up in the pipe.

 

Do you know where the pipe terminates? Outside somewhere? Floor drain?

 

Typical..... no one takes the condensate drain line seriously until it's clogged.
It's not supposed to run like that. Not enough pitch.

Easiest thing to do is to find the other end and connect it to a wet/dry vac and suck it clean.

 

I just checked the pipe and it ends where the sump pump is. I would have to move the well cover to get to it. I'm not sure what it looks like past where it enters the well through a hole in the cover as I first need to move a bunch of stuff to get to it. However, I can say that a flexible plastic hose is attached to the PVC pipe and it's the hose that goes into the well. The hose has a rather smaller diameter than the PVC pipe and I'm wondering how the wet/dry vac will manage to function. I assume I could wrap some towels or something around the connection between the plastic tube and the vac hose.

As for taking the condensate drain line seriously, I didn't even know what it was until last night. Hard to take it seriously when you don't know it exists. As far as I knew, it was a pipe -l ike all the PVC pipes in the house. This isn't my area of expertise. But now that I know about it, what do I do to maintain it? To keep it clear? Do I have to use the vacuum on it periodically or is there something easier to do?

 

If you have access to an air compressor you could blow it out from the Air handler end, to keep it clean, every 6 months or so pour a 50/50 mix of bleach and water into the PVC at the air handler end.
Geo

 

You'd have to modify the drain line at the unit to use a compressor. If you just shoot air in there it will blow into the unit splattering water everywhere.

Take that flexible hose and stick it into the suction side hose of the wet vac. You could wrap it with a little bit of tape. Be sure to remove the dry filter from inside the vac before using it on water.

During the cooling season..... pour a cup of bleach mixed with a cup of water down that open pipe by the unit. Usually once a season is enough. You could do at the start and then again midway thru the season.

 

Thanks guys. I don't have an air compressor, but I do have a wet/dry vac, so I'll go with that. I'm going to attempt to clear the pipe this afternoon. I hope I can rig it up well enough to vacuum out whatever is clogging the pipe. And I sure hope it makes it through the narrower tube!

I'll let you know how it goes.

 

The pipe leaving the A/C is 3/4" PVC pipe. That means the inside is 3/4" of an inch. Perfect size for a condensate drain. Restricting it smaller at the end is where you'll get the backup or clog.

It won't take much to clear the line.

 

 

Success! I pulled to tubing out of the sump pump well and stuck it inside one of the vac attachments. It's a smaller one for sucking up water. The opening for it is about 3" wide and a little less than a inch thick. Then I used duct tape to cover the remaining opening and keep the hose attached to the vac attachment. At first it didn't look like anything was happening, but then I could tell it was sucking up water, so it did clear the clog. I didn't see any actual lump of anything in the vac when I was done. I left it all attached until I was sure water wouldn't back up again. It's been hours and no water leaking!

And now I know to keep the line clean with a bleach/water mixture. I do have a quick question about that. I'm pretty sure I know where to pour this mixture, but I want to double check. I looked for pictures and while the location and size of this pipe varies somewhat, it's always perpendicular to the drain pipe and has a cap on the top. There would be just one of these right? And it would be close to the unit, correct? I ask because I can see such a pipe about a foot to the right of where the right side of the picture I posted ends. As I said, the pipe from the furnace to the sump pump well is behind a bunch of stuff so I can't see it easily. I can't imagine there'd be more than one perpendicular pipe, but I thought I should ask before pouring bleach where it doesn't belong.

 

You can pour it in that trap right at the unit or to be sure the condensate pan inside the unit is clear you can pour it in there and let it drain out the way it supposed to.

Geo

 

Your arrow in the picture is pointing to where the solution should be poured in for cleaning the drain line.
You mentioning an additional vertical stub suggests that you may have a condensing gas furnace which also uses the same drain line. You could post an additional picture from further away so we can see the whole unit.

 

It would be hard to take a picture from any distance of that other pipe with the cap on it as it is just to the left of the furnace/AC, meaning that it's behind the furnace/AC unit if you're looking at it from the front. I can't get a picture from the side because that's where the refrigerator is. All you'd get is a picture of the pipe essentially from the top down. Not too useful.

But if I can pour the mixture in the pipe above where the arrow is in the picture I posted, then I can do that. Btw, shouldn't that pipe have a cap on it? Not sure it really matters as the area where the two pipes connect (exactly where the arrow is pointing) isn't actually a fitting. I can stick my finger in between those pipes (not far in, but still...)

In any case, both the pipe in the picture and the taller pipe I described that I can't take a picture of both lead into the exact same pipe that goes behind the fridge and around the corner and behind the washer and dryer.