Bathroom sink drain not used but maybe 1x per day to wash hands.

Backed up a few years ago, took apart trap and cleared out a bunch of paste like stuff in the trap and connections. Gross...drain worked fine since then.

Recently won't drain. Happend kind of suddenly. Did same proceedure but when I reconnected then washed my hands, it filled up and would not drain again. Took everything apart, put snake down drain (into wall), felt what I though was a clog, in-out-in-out turn....hear water clear out and drain.

Success...nope. Reassemble and it still fills with water. Tried snake again but could not find any plugs to ~20 feet or so. Used a pressure plug (hooked to garden hose) water runs and runs in hose but system never seems to fill or back up.**

Reassemble..same thing. Sink/trap quickly fill with water and will not drain.

NOTE: When I disassemble the trap everything drains into the bucket under neath. Even a little back flow from the pipe going into the wall.

Anyone have a suggestion?

** Though maybe it was backing up into vent but if that were true, it would dump a ton of water into the cabinet and all over the place. When my son turned of the hose, a little bit of water dumped out from the wall (maybe 2-3 cups). Other than that, the outlet was dry.

tree root

Upstairs sink and I only got ~10-feet of snake into the drain. I doubt it's a tree root.

Problem at the stopper? I see some that are holding the water at the stopper because of a little piece of rubber or the design. Sounds like it has to be at the top end of the system, you have cleared and checked everything else.

nope...the system has the AC condensate drain attached below the sink and the sink fills up with cold water. And when I disassemble the traps water comes flushing out from both sides.

I don't know if this will help, but when I had a similar problem, I ran a snake down the roof vent and cleared out a clog. All was well after that.

I also found out that Drano (and such products) calsifies in pipes and only makes matters worse! Be careful with that stuff! I won't use it anymore.

Don't use drano.

Thought about the vent, but the toilet and shower both connect to that drain (on same wall) and drain just fine. Also, if it were the vent, I'd likely hear gurgle noises coming from the shower when I flush the toilet. I don't.

Plumber is coming out to diagnose and give me an estimate. If it's too much, I'll get to the vent and try to run a snake down that end as well.

It's strange that I heard water flush out the first time I used the snake, but it's still clogged. I suppose I could have just shoved the clog further down the system.

Similar thing happened to us. An upstairs bathroom sink that is rarely used kept backing up with water. I did the same thing you did but it kept happening. We had a plumber come out for a different reason and he said the drainage from the AC condensate was creating mold. He cleaned it out and then said to pur 1/2 gallon of clorox down the drain about once every quarter to kill the mold. Have not had a problem since.

quote:

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I ran a snake down the roof vent and cleared out a clog

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We also had a problem (feminine product) that was partially blocking our toilet drain. My hubby snaked it from the roof vent and the solved the problem.

Well the blockage I'd hit earlier I only partially cleared. The plumber put the snake in ~2-feet and got the rest of it cleared.

I thought I was hitting a corner but it was actually the blockage. It's all clear and I'm $129 poorer....don't you hate it when you're 9/10th done but can't get that last part and it turns out to be something easy. I should have kept after it a little longer and I'd have fixed it.

The pipe goes into the wall and turns 90° to the right. Water would always drain out of that wall section when I uncoupled the P-trap. I'm betting it is not sloping down and there was a partial blockage in that not quite horizontal which was backing things up enough to cause the problem.

I know about the bleach thing now and will be doing that in both the bathrooms that have AC drains.

lesson learned...keep at it for a little while longer..

Whenever I solve problems like this in the house or with the car I always tell my wife what I fixed and hold my hands up and she rolls her eyes and says "you're the man"...Tuesday, I fixed the SRS light on the van (reset it manually) and I told her I can only be "the man" once per day and that's why I did not get the plumbing fixed that night

[This message has been edited by agracer (edited 7/8/2011 8:19a).]