undefinedundefinedundefined :mad: Our house is 4 years old. We are on town water and sewer, no septic tank. There is a Drain Waste Vent on the outside wall of the house, directly behind the kitchen sink area. The end of the vent has a slotted cover. Approximately 1 month ago, I noticed that whenever the kitchen sink or dishwasher was running, instead of the water draining through the pipes down to the basement, it was draining out the Drain Waste Vent to the outside of the house. I looked through the slots of the vent and noticed that there was food buildup in the drain. Since the vent cover was unremovable, I tried my best to clean the drain out with a hose, by directing the flow of water through the slots. I did this for about 15 minutes, but as soon as I shut off the hose, the water would come roaring out of the vent again. At this point I contacted two plumbers. We had the second plumber fix the problem, as his solution was simple and inexpensive. His solution was to extend the length of the vent, cover the end, then install an n shaped pipe to the top of the DWV. The new opening at the bottom of the n on the DWV has a slotted cover, as before. The procedure fixed the problem in that the kitchen sink and dishwasher now drain to the basement, although you can hear a gurgling sound coming from the vent if you go outside. Today, while sitting on my back porch I smelled what seemed to be sewage odor. I went over to the vent and discovered that the vapors coming out of the new pipe smell like raw sewage. Since this DWV is only for the kitchen sink and dishwasher, I assume that the odor is from decomposing food, not sewage. At any rate, it smells awful and the odor can be detected from several feet away. Today was a very warm and humid day which probably compounded the problem. The first plumber that came out to our house(the one we didn't use), before the plumber that put the new pipe on, told us that when they built our house, the pipe running from the kitchen sink to the basement was not pitched properly, thus gravity was not doing its job and causing the water to back up to the outside. The plumber who installed the new pipe said that while the pipes could have been pitched more, insisted that his solution would take care of the problem. Bottom line, drainage problem is solved, but sewage odor has created a new problem. I tried pouring baking soda and vinegar down the drain and running the garbage disposal, but the odor remains. Please advise what we should do to resolve this problem. Thank you in advance.

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Originally Posted by Andyrose

undefinedundefinedundefined :mad: Our house is 4 years old. We are on town water and sewer, no septic tank. There is a Drain Waste Vent on the outside wall of the house, directly behind the kitchen sink area. The end of the vent has a slotted cover. Approximately 1 month ago, I noticed that whenever the kitchen sink or dishwasher was running, instead of the water draining through the pipes down to the basement, it was draining out the Drain Waste Vent to the outside of the house. I looked through the slots of the vent and noticed that there was food buildup in the drain. Since the vent cover was unremovable, I tried my best to clean the drain out with a hose, by directing the flow of water through the slots. I did this for about 15 minutes, but as soon as I shut off the hose, the water would come roaring out of the vent again. At this point I contacted two plumbers. We had the second plumber fix the problem, as his solution was simple and inexpensive. His solution was to extend the length of the vent, cover the end, then install an n shaped pipe to the top of the DWV. The new opening at the bottom of the n on the DWV has a slotted cover, as before. The procedure fixed the problem in that the kitchen sink and dishwasher now drain to the basement, although you can hear a gurgling sound coming from the vent if you go outside. Today, while sitting on my back porch I smelled what seemed to be sewage odor. I went over to the vent and discovered that the vapors coming out of the new pipe smell like raw sewage. Since this DWV is only for the kitchen sink and dishwasher, I assume that the odor is from decomposing food, not sewage. At any rate, it smells awful and the odor can be detected from several feet away. Today was a very warm and humid day which probably compounded the problem. The first plumber that came out to our house(the one we didn't use), before the plumber that put the new pipe on, told us that when they built our house, the pipe running from the kitchen sink to the basement was not pitched properly, thus gravity was not doing its job and causing the water to back up to the outside. The plumber who installed the new pipe said that while the pipes could have been pitched more, insisted that his solution would take care of the problem. Bottom line, drainage problem is solved, but sewage odor has created a new problem. I tried pouring baking soda and vinegar down the drain and running the garbage disposal, but the odor remains. Please advise what we should do to resolve this problem. Thank you in advance.

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"the plumber that put the new pipe on, told us that when they built our house, the pipe running from the kitchen sink to the basement was not pitched properly, thus gravity was not doing its job and causing the water to back up to the outside."
Something just doesn't sound right here. The sink hookup goes like this. Sink to trap, trap to lateral, (The horizontal pipe in the wall and the only one that is sloped), lateral to the vertical sink drain/vent, sink drain to sewer main. Unless you have a unusual configuration there's no way the plumber check the slope on the lateral unless he opened the wall up and the vertical drain to the basement gives the discharge extra energy and rate of flow by the time it gets to the main. Also when you drain your sink you start with at least a four inch head of pressure from the drain to the trap. What am I missing here?
I hate to call another plumbers work into question but did the vent and drain ever work? Please explain about the "N" shaped pipe. This "Drain Waste Vent" sounds like a Studor Mechanical Vent. Is this the case? What you have sounds like a partial blockage. What happens with a partial blockage is the discharge hits the blockage and bounces back sending a bubble of air ahead of it. You might be smelling sewer gas sent back up the vent.

"Since this DWV is only for the kitchen sink and dishwasher, I assume that the odor is from decomposing food, not sewage."

Not so! The vent has a direct shot to the sewer.
Please explain a little more about how your plumbing is installed. Why is there no vent from the kitchen sink to the roof? Why, when the water backed up out of the vent didn't it come up in the sink? The sink's lower then the vent and water seeks its own level. There's a lot I don't understand, please help me out. Regards, Tom

Hi Tom,
Thanks for writing in. I know nothing about plumbing, but I'll try my best to provide you with more information. I believe that the kitchen drain pipe runs on a slope through the basement to the main drain. There is a roof vent which is somehow connected to this drain, so in effect there are 2 vents. One vent is on the roof and is for the toilets and kitchen sink. I don't know why they put in this extra vent outside the kitchen wall, but I'm assuming that it was installed to make the kitchen drain work more efficiently. I think that when the water backed up out of the vent it didn't come up the sink because it was a partial blockage. I even tried sealing the slotted vent and was very surprised when the sink didn't fill up. You are right that the odor I'm smelling is coming from the sewage. We had friends over for dinner tonight and one of them is an engineer. He looked at the configuation and told me that the builder did not build to code. He said that the vapors coming out the DWV are from waste. I don't know what a Studor Mechanical Vent is, but I can explain the vent we have as follows. The kitchen drain pipe runs down from the sink to the basement, where it joins another pipe. In the basement, the left side of the pipe runs towards the basement drain while the right side of the pipe runs out the wall to the DWV. The DWV extend about 6" out from the outside wall. The plumber cut a hole in the top of the pipe and installed another pipe that loos like an n. It rises up from the pipe coming out the outside wall, then curves in an n shape and the end of the pipe faces the ground. There is a slotted grate at the end of the n extension facing the ground. The pipe that is coming out the wall has a removable cleaning nut at the end so that the pipe can be snaked out if needed. As mentioned, since the plumber added the n shaped connection, we no longer have water coming out the DWV. The friend who was at my house tonight said that the best solution was to put a charcoal canister at the end of the slotted vent that is facing the ground. He said that that would solve the problem. All the houses in my neighborhood were built with this DWV coming out the wall of the house. Every time a workman sees this device they wonder what it is. The guy who came tonight said the same thing. He wanted to know why the kitchen sink wasn't vented to the roof. At any rate, it looks like it is vented to the roof as well as to the DWV which runs to the outside wall. I hope that this information is of help to you. Thank you very much for your input.

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Originally Posted by Andyrose

Hi Tom,
Thanks for writing in. I know nothing about plumbing, but I'll try my best to provide you with more information. I believe that the kitchen drain pipe runs on a slope through the basement to the main drain. There is a roof vent which is somehow connected to this drain, so in effect there are 2 vents. One vent is on the roof and is for the toilets and kitchen sink. I don't know why they put in this extra vent outside the kitchen wall, but I'm assuming that it was installed to make the kitchen drain work more efficiently. I think that when the water backed up out of the vent it didn't come up the sink because it was a partial blockage. I even tried sealing the slotted vent and was very surprised when the sink didn't fill up. You are right that the odor I'm smelling is coming from the sewage. We had friends over for dinner tonight and one of them is an engineer. He looked at the configuation and told me that the builder did not build to code. He said that the vapors coming out the DWV are from waste. I don't know what a Studor Mechanical Vent is, but I can explain the vent we have as follows. The kitchen drain pipe runs down from the sink to the basement, where it joins another pipe. In the basement, the left side of the pipe runs towards the basement drain while the right side of the pipe runs out the wall to the DWV. The DWV extend about 6" out from the outside wall. The plumber cut a hole in the top of the pipe and installed another pipe that loos like an n. It rises up from the pipe coming out the outside wall, then curves in an n shape and the end of the pipe faces the ground. There is a slotted grate at the end of the n extension facing the ground. The pipe that is coming out the wall has a removable cleaning nut at the end so that the pipe can be snaked out if needed. As mentioned, since the plumber added the n shaped connection, we no longer have water coming out the DWV. The friend who was at my house tonight said that the best solution was to put a charcoal canister at the end of the slotted vent that is facing the ground. He said that that would solve the problem. All the houses in my neighborhood were built with this DWV coming out the wall of the house. Everytime a workman sees this device they wonder what it is. The guy who came tonight said the same thing. He wanted to know why the kitchen sink wasn't vented to the roof. At any rate, it looks like it is vented to the roof as well as to the DWV which runs to the outside wall. I hope that this information is of help to you. Thank you very much for your input.

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Hey Andy,

I got to see this setup. Can you take pictures of the "N" fitting. (running trap?) or the slotted device ,(Studor Vent?) and post them here? If not my addy is [email protected]. Pop over to Studors site and tell me if this is what you have. http://www.studor.com/homeowners.htm
Two vents on one fixture is not only redundant, it's downright unheard of. Either you have some weird local plumbing codes or your entire project has a major plumbing design flaw that plumbers are now attempting to compensate for. Let me give you the typical drainage layout for a kitchen sink. Sink drain to trap, trap to wall stubout, a elbo and a horizontal,(lateral) pipe that's inside the wall the connects to a sanitary tee on a upright pipe, also inside the wall, that runs up to the roof for a vent and runs down to the basement under the cement to tie into the house main. If local code allows, a washer trap and standpipe may discharge into this pipe and be wet vented by it. What''s all this "slotted vent" and "N" fitting nonsense? If it were me I would get me a sharp plumber out there to tell me just what's going on with your installation. If he found code violations and a sloppy job of plumbing design I would take his affidavit, contact my neighbors and mount a class-action suite against the builder/contractor, the architect that oked the plumbing layout and the plumbing company that installed the work. Your drainage installation is not normal and unless there's some special reason that it's not I would for sure want to know why.
Please keep me in the loop on this. Incompetence makes me angry and if the entire development was plumbed with two vents serving one fixture that would indicate gross incompetence. Regards, Tom

Tom,

There is one narrow plastic regular pipe sticking out of my roof, another wider aluminum pipe(looks similar to the Studor Vent) sticking out of the roof and the DWV coming out the back of the house. I emailed pictures of the DWV to you. Thanks.

Andy

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Originally Posted by Andyrose

Tom,

There is one narrow plastic regular pipe sticking out of my roof, another wider aluminum pipe(looks similar to the Studor Vent) sticking out of the roof and the DWV coming out the back of the house. I emailed pictures of the DWV to you. Thanks.

Andy

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Thanks Andy,

It's all coming together now. There was a design oversight when your plumbing was designed. A roof vent for the kitchen sink was over looked, (why the plumbers that did the work didn't complain and why it passed inspection I'll never know). If as you say the drain pipe from the sink goes straight down to the basement instead of going into the wall then you have a "S" trap installed which is outlawed in all plumbing codes in the United States and Canada. To compensate for a vent that should have been included at the very first rough in they teed off from the drain pipe in the sink and ran a vent out the wall. This worked for a while until food begain to build up in the drain and begain to back up out of the DWV in the wall. We call this a "partial blockage". The plumber is now faced with a problem. He has a partial clog that's backing up out of the wall vent but no roof vent he could snake the drain line out of. So he did the only thing he could do. He cut out the old wall vent and installed a combination vent and clean out. What you have out there is a 2" PVC drainage tee on its back with a clean out on the end where the old vent was and a 2" elbo with a streel ell turned down, (your "N" fitting) with a "rodent grill" installed in the end to keep out the critters as a vent. The way it was installed originally almost guaranteed that in time you would start to get some of the discharge backing up out of it. By raising the vent to a return bend stopped the backup out of the old DWV and you now have a cleanout that you can snake out the line , however there's still enough resistance in the drain to send a puff of sewer gas out the vent. This is what you smell and this is why we run our vents out of the roof. As I see it Andy, you have two options. You can cut the return bend out and run a pipe higher up the wall to exhaust the sewer gas in the air instead of your nose or like yoiur friend suggested cover the vent with a charcoal filter. However I see a problem down the line if the filter clogs up and blocks the vent. The fact that a entire project passed inspection with this design flaw makes me wonder if the contractor had a "tame inspector" in his pocket. If the houses were roughed in and the walls went up before anyone noticed the kitchen vent was missing, (unbelievable!! ) then it would have cost the builder big bucks to rectify the situation. Instead you got a "Band-Aid" fix and there's not much you can do at this stage of the game.
Andy, I really want to thank you for bringing me in on this. This is what makes answering questions fun for me and why I enjoyed my job as the shop trouble shooter so much. To sum this up. Ya got to bad plumbing job, sport! I blame the general contracter as I can't conceive of any plumber installing a vent, such as you and your neighbors have, without a direct order to do so. I've taken the mystery out of this to my satifaction and I hope it it explains some of your questions also. Good luck, Tom