Can a person knowledgeable in HVAC help a doper out?

So I have had some leakage on my basement floor. Took a while to find where it was coming from, but it is coming from fine streams of water coming out our furnace/AC. Here’s a pic.


At least one of the leaks is coming out near the “top” PVC pipe, which I believe is coming out of a condenser. I have unscrewed the top of the T joint in the PVC pipe and it has been near the brim of the screw hole the entire time since I’ve noticed the leaking on the floor. I don’t know if it is always supposed to be like that due to the P trap, but I have left that cap open for now so that it leaks out there, going into my janky dustpan/pot contraption. This pot can fill up in a day completely.

I suspect the top PVC pipe is blocked and shouldn’t be, somewhere.

Now, the “bottom” PVC pipe is just loosely hanging over our french drain. For some reason, the top PVC pipe is cemented into the french drain. If there is a blockage, I don’t know where it is.

For anyone with experience, what is going on? Is this something I could somehow resolve myself or do I have to get someone out here?

I believe most people with a basement will have those pipes empty into a small pump that pumps the water to the nearest drain or outside. Your system looks to rely on gravity for the water to exit the house?

The first step would be to clear the exit holes. A lot of times they will leave the PVC without sealing it because it’s not a pressure system. You might be able to just pull apart the PVC at the joints. If its all sealed up you might have to snake it.

Have you had a lot of rain? This might be an early indicator that the French drain is clogged and you have standing water against the concrete of your house and the pressure column is backing up through the pipe.

Do you have a nearby deep sink or floor drain?

A condensate pump runs about $45 and would pump the water into small clear flex pipe that you can run to a drain or deep sink. I don’t know your finances but it might be smart to install one just for now as you figure everything else out. The cost of the entire system would be cheaper then a service call from a HVAC tech.

My AC condensate line (Southeastern US) occasionally gets algae growth, which causes the water to back up, which will end up tripping a float switch and killing power to the AC. Quickest solution is just to put a shop vac on the outlet of the condensate line, suction all the crud/water out, and run a cup of vinegar (or diluted bleach) down the line.

I just had to do this myself. The drain pipes get clogged with algae and back up. In my case, I could go outside and put a shopvac on the end of the pipe in the yard and suck the pipe clean. In the OP’s case, it sounds like that isn’t really possible because the end is in the french drain. If you can’t get to the end of that top pipe where it drains, you may have to fix this from here.

Here’s what you may want to try. Get some flexible tubing. Put one end in the top of the PVC and push it to the bottom of that PVC u-shaped curve. Put the other end of the tubing below the PVC and create a siphon. (check youtube for videos if you’ve never siphoned). Siphon as much water as you can into the bucket. This should clear the water from the PVC above the level of that u-shaped curve. Then you can pour in vinegar and it should dilute into the remaining water in the pipe to kill the algae. You may want to use bleach for a stronger effect since it will be diluted.

An alternative would be try to “plunge” the pipe much like you would do with a sink. It will be a bit challenging because you can’t use a traditional plunger. You’d have to figure out something to be able to plunge the water in that PVC. You can’t just plunge at the top since the force would go to left where the PVC goes into the AC. You’d have to figure out a way to plunge so that the force only went down into the PVC pipe that goes outside.

If the pipe gets full, it causes water to back up into the part with the coil and that water can trickle down. The water you see trickling out in other places is likely coming because of this backup. Once you clear that top pipe, the other leaks should stop.

According to this:

If you can’t access the outlet of the condensate line, may want to try to hook up a garden hose to the inlet side. Of course, by doing so you run the risk of getting even more water everywhere depending on how severe the clog is.

We are in Ohio, and our furnace/AC system is in the basement. When our new furnace was installed a few years ago, the installer put in a small sump pump to capture the water coming from the furnace. The outlet hose from the pump went up, through an outside wall, and dumped the water outside.

The furnace produces water year around. In the summer the AC is on, so the evaporator is producing water. In the winter the propane furnace is on, and water is a byproduct of the combustion. In both cases, the water goes to the pump and then is routed outside.

It worked well until winter. And then the water hose outside the house froze up. :disappointed_relieved:

So I replumbed it. When the water exits the pump, it first goes through an acidic condensate neutralizer, and then through a long hose to an existing sump pump in the far corner of the basement. The sump pump pumps this water - and water from a wet bar - into the septic system. Works like a champ.

I had something similar, but it was coming from the ducting on top of my furnace.

Basically - a new house, the overall ducting was not completely clean. The air conditioner cooling coils are an A-frame arrangement in the ducting on top of the furnace where the air exits. The furnace fan blows, the air goes over these coils and cools.

In humid times, ice or condensation will form on the condensers sometimes. When the air conditioner stops, the air melts this ice, it runs down to a trough at the base (the legs of the “A”) the cooling coils sit in. From there it runs into a tube much like yours, but minus the trap. (and from there through a clear hose to the sump drain) So the overall setup seems to be the same as yours.

When the house was built, they did not do a good job cleaning things. The spot where the pipe drains from the ducting was full of tiny wood bits and fluffs of insulation. When this clogged up the drain, on humid days with heavy flow, the trough would apparently overflow and water would run down the side of the furnace and all over the floor.

The furnace guys cut a hole in the side of the ducting (and put a cover over it) to clean the interior, and also sucked out the crap in the drain hole. I haven’t had a recurrence since.

So it seems your problem would be the drain hole at the top isn’t draining if water is coming from the top of the furnace.

So from your picture and description, it sounds like you took a cap off the top of the T joint, and that’s where the water is coming out? I’d try snaking first - as others have said, you probably have algae build up in the P trap there. I’d just try snaking that first, since getting a shop vac on the far end of that drain is difficult/impossible.

The water was coming out a seam in the housing near that T joint, I uncapped the t joint just to have a controllable place for it to pour out.

We took some combined advice from here and just kind of used our fingers as a plunger til we heard a “glug glug glug” sound and the water lowered, then we poured a bottle of vinegar down the hole and it took the whole thing.

Fingers crossed this sorts it out. Thanks for the help so far guys.

I’m guessing the reason the T joint was there was to give you access to the pipe for cleaning reasons anyway. Otherwise they could just have used just an elbow

The condensate water is coming from you evaporator coil. The condenser is outside with the compressor. I still would use a shop vac to suck the last of the sludge from the trap. And after words I would put about a gallon of water to flush the drain and reestablish the trap seal. Having the condensate drain plug up with slime is a common problem on soe AC units.

If this is a condensation line, and it is clogged (as mine is partially currently), there is a pretty simple solution if you own a compressor or have a friend with a compressed air tank. Since you can take the drain apart near the top and you have eliminated at least the top half of the standing water, wrap a towel or rag around an air nozzle and shoot some air down there. It is the top end equivalent of sucking the other end out with a shop vac as suggested above. Just make sure you have a pretty good seal at the top so dirty water doesn’t shoot back out the top at you.

As long as there is a place for the water/air to go at the far end of the line, this will clear out the pipes to a very large degree. If it just wants to blow the air nozzle out then there is a more serious clog somewhere in the pipe or at the end of it. (If for example a lizard climbed a small way up the pipe then died in there and is fully blocking the thing.)