View Full Version : Ventless or external vent on toilet??

12-31-2005, 03:10 PM
I have a toilet installed w/o a vent pipe. Originally a siphon toilet wouldn't flush very well (especially solids). I found a toilet with a closed internal tank that seems to force things down using some pressure and this works much better (usually 2 maybe 3 flushes to get all the solids down but at least they go down). However about every other time after flushing the water in the bowl still gets sucked out until you hear a gurgling sound as air vents into the main pipe through the bowl.

Do they make a toilet with an external vent attachment (which I could then tie into the vent stack from the sink) or a 'ventless' toilet to allow air in but keep the smell out? If so where do I find/order? I know there must be slight pressure in the main line which is preventing a normal siphon toilet from flushing and causing the water to get sucked out 5-10 seconds after most flushes.

I know the proper thing is to bust up the floor but that would be difficult for various reasons. Local plumbers have been no help and could not even identify the original problem.


Mike Swearingen
12-31-2005, 05:24 PM
Why do you have a toilet (or any other fixture for that matter) without a vent?

12-31-2005, 06:15 PM
An air admittance valve would stop the "sucking" of water out of the toilet, (after a certain point), but would do nothing to eliminate the air pressure that is preventing the flush.

12-31-2005, 09:07 PM
Thanks for the 'air admittance valve' suggestion, I will research that for information, those are the type of suggestions I hope to get.

With the current toilet (which has an internal tank under pressure to help force the flush) it flushs 'ok'. If I could just somehow slowly vent the pipe below the toilet w/o jack hammering up the concrete that would work, for now.

As to 'why' we have a toilet w/o a vent :) I think the answer is pretty obvious, bad construction by some previous owner in an unpermitted extension. A very common answer to most 'why is it like that' questions in this forum, very very bad construction.

Thanxs again for any thoughts on possible solutions to venting the main pipe from above in a poor construction situation.

01-01-2006, 04:45 AM
Depending on what you want to spend this is what you could do. Call a sewer cleaning service that also does camera work and have the line snaked and send a camera down the line after that. This will let you know what the problem is. They also can locate it and tell you where and how deep it is. Call around for prices and be sure to find some one who does both as they should be the most reasonable. They can even put it on tape for you to watch when your bored :) . They could just snake it and then try the toilet but if it didn't work they would have to pull it again. HJs idea for the AAV is great, perfect situation.

01-01-2006, 06:06 AM
One problem with an AAV is that you have to have somewhere to connect it to the pipe. From you last description, you may not have that point.

01-01-2006, 12:35 PM
I looked up the AAV valve for info and HJ from your last post you are correct. I don't have an easy place to connect that into the main drain line. Still I didn't know that AAV's existed and that would have helped me vent the sink which originally had the same problem (I ended up tearing out a piece of drywall behind the sink and put in a vent pipe, I could have used an AAV valve instead). Unfortunately I can't do the same thing for the toilet.

I guess I was hoping there was a toilet manfactured with something like an internal AAV valve in the tank and a small feeder air line built into the porceline to tap behind the siphon mechanism. Then I could just buy a new toilet and put it on top.

So many gizmo's I was hoping such a thing existed (ie., a self ventilating toilet that does not require a vent pipe or has an above ground connection for a vent pipe).