View Full Version : Draining tub or wash machine sucks water out of toilet,HELP?...Please!

06-09-2006, 02:10 PM
Hello everyone, this is my first post to your site.
I am new to owning a house and to attempting any type of plumbing. Dad says you do not need to know much about plumbing except s*** flows downhill.
I used to work as a plumbing/ heating shipper and reciever so I am familiar with some products and how to put them together but not with much else.
The house I purchased is about a hundred years old. All of the plumbing is/was copper. It has a dirt basement. Most of the plumbing is NOW on the northwest wall. The kitchen, bathroom and laundry. I have moved the kitchen and laundry from their original location a few feet to aid my new floorplans. The bathroom stayed basically where it was with the exception of the bathroom sink. I took that out for the time being while framing new walls to make the bathroom bigger. I put a rubber quick plug over old drain. I also will move the location of the bathroom sink and have made the necesarry provision in the new drain already installed for the wash machine, (all I have to do is unscrew a fitting plug in the abs tee and connect the drain) The branch of plumbing that that old bathroom sink was on is now sealed. I am thinking that this was what you would call a wet vented sink as the drain attached to the plumbing below the floor at a 90 degree angle with a pipe that went outside to vent straight up from that. I found it strange that it was 2 inch while the rest of the plumbing was 1 1/2. I cut that out too so it was not in the way. Did I remove the vent for the toilet? I think so but I thought the new vent I made for the wash mach. tub bathroom sink would share that. Maybe that branch of pipe I sealed off (about 4 feet long)is acting like a vacuum chamber to disrupt the airflow to the new vent as it is on the other side of the toilet from my new vent? Most of my work is abs coupled to the existing copper. When I flush the toilet it seems ok but sometimes it takes a couple of flushes. Was a lot better before. When draining the tub the toilet bubbles and the water is sucked out of the toilet right about near the end of the tub draining , does the same thing when the washer drains. Does the toilet have to have its own vent? Is that my problem? My girlfriend really is not happy with me for fixing the house by making it worse than it was. I was quite proud of my kitchen sink vent as the sink drains like an airplane toilet if you arent carefull it will sunk your arm in. Boy was I chopped back down to size when I did this to the toilet. I guessed Dad was wrong when he said that about plumbing. I phoned him to tell him about this and he did not have a clue how to help. I asked him how he figured there was not much to know about plumbing when he can't help me out with this. He said it sounded like a funny expression to get me to try it myself. thank you for reading this it maybe a little confusing sorry no pictures

06-09-2006, 02:29 PM
Sounds like you need to work on venting everything correctly; I think you are right, about it not now being correct. Basically, each drain should be vented...water traveling past an unvented trap can cause all sorts of things. Can you maybe make a small drawing of what you have and attach it in an update.

06-09-2006, 02:48 PM
Yes, I will try to make a drawing to attach, it may take a few minutes to figure out how to use the feature, I am even less compotent with a computer than with plumbing. I will try paintbrush maybe the kids can help me, they are on the computer quite a bit using that. Wait, I have an idea, maybe they would be more successful at plumbing too. Thank you for the reply, goin drawin..

06-09-2006, 04:43 PM
After looking more carefully and having to actually draw a picture of this set up it appears that maybe my toilet is trying to draw air through the fixtures hooked up to the new vent as well as the vent itself. I think maybe the toilet vent needs to be closer to the toilet itself. I am not sure, what do you think? I hope you can decipher this picture, it is kind of crude. Maybe that long loop the air has to travel through builds up a vacuum????

06-09-2006, 04:50 PM
I leave the specifics to the pros with experience...one will show up eventually. I try to field the easier ones! and brainstorm on some of the weird ones, too, while learning myself.

06-09-2006, 08:17 PM

That's one nasty looking picture.

The toilet needs at least a 2" vent on it.
The kitchen sink should have it's own vent.

The laundry, how many times should I say this? needs a vent, which it can share with the laundry tray.

the bathtub needs it's own vent, seperate from the washer.

Vents can be tied together above the flood level of the fixtures served. 42" worksl pretty well for that.

Get rid of that goofy looking p-trap in the drawing.
Every fixture except for the toilet gets their own p-trap.

06-10-2006, 12:41 AM
Yes indeed, this is a nasty picture, I guess only I can understand it. Well, at least I know it worked. I needed help to figure out how to send a picture, and I am not a great artist. I just got back from home depot and explained the problem to him with my diagram, he was helpful and I think I will move the toilet and tie the other abs I have upgraded to into that while installing a vent for the toilet. He gave me the 3" fittings I needed, but he said I needed only 1 1/2 inch vent? my fixtures do all have p-traps I just did not choose to draw them but rather illustrate the area I think have the problem. How far from the toilet can the vent be? Does it have to be 2"vent pipe ? I already bought 3x3x1 1/2 tees (3 of them), one 3" long sweep 90, a toilet flange and a 3 "" flexible quick coupler to adapt to the main line. all that I need is the abs pipe. How do I put the flange in the floor for proper finished look.? I will finish with tile or should I do that before moving the toilet and set it on the flange which would be on top of the tile?. I may rebuild the floor, not sure yet. What is a laundry tray? I did not recieve that message, Thank you

06-10-2006, 03:26 PM
Regarding the toilet flange, yes, it should be installed on top of the finished floor. If tiling, it is easier to notch the tile where the anchor bolts will go so you don't have to drill through it, which can be a pain if it is one of the hard porcelains.

06-19-2006, 12:50 PM
There is not much, if anything, about that system, as drawn, that does not need to be revised. HOME DEPOT for advice on a drain/vent system? They also think the only thing you have to know is which way water flows, although they might add that they also try to remember when payday is.