We have had a sewer/gas smell in our laundry room on and off for about a year now. At first we thought it was coming from our new Kenmore front load washing machine as we would get the smell when doing laundry. We had a plumber take a look and he snaked all the drains and said the outdoor pipe had some branches stuck in it. Everything else was fine. No smell for about a month then it came back again. I noticed the smell only starts when we use our electric dryer - not the washing machine! I found this out as one day I put some damp clothes in the dryer (washing machine hadn't been used in days) - and after the dryer was running about 5 minutes the smell started. Any idea what could cause this? Doesn't seem like a plumbing problem but I am not sure. No idea what type of repairman to even call for something like this. I have also noticed that our bathroom sink on the 2nd floor above the laundry room will sometimes have a sewer odor coming from the drain. This will happen maybe once a month and all I do is poor some Drano down and the smell stops. The smell doesn't seem to occur during the same time we are doing laundry.

Is your washer draining into a trapped drain? Bet not, just a stand pipe and that allows sewer gas to enter your home when the dryer evacuates some air from the room. Try capping your stand pipe with Saran wrap and duck tap and I'll bet the odor isn't there. Have your plumber come back and build you a trap if you are'nt sure how to do it.

We do have a standpipe but it is connected to a trap drain. We will give the saran wrap a try and see what happens. Thanks

Some trapped stand pipes using an S trap rather than a P trap. The S trap can siphon dry and can no longer be installed.

I tried sealing off the drain pipe with Saran wrap and duct tape. It didn't help. Once again I didn't run the washing machine at all (havent for 24 hours). I put some wet clothes into the dryer and within 15 minutes the smell was there. Could this possibly have anything to do with mold? I have heard a lot of talk about black mold behind walls.

It is possible but mold does not smell like sewer gas. It could even be lint in your dryer that is getting musty and moldy. Have you checked out the dryer vent pipe and insides of the dryer chamber?

Our dryer vent goes directly from our dryer straight outside. There is only about 3 feet of alluminun vent. It is clear of debris. Our dryer is only 1 year old and the vent trap in the dryer is cleaned after each cycle. The smell occurred one of the first times we used it. The same smell occurred with our old dryer as well. The smell can sometimes me more of a gas smell and other times it almost smells rotten. A couple years ago we had an issue with our upstairs bathtub having a crack and it was leaking (right above our laundry room). Once we noticed the leak we stopped using the tub and we just replaced it last year. When we were installing the new tub/shower we had to cut a hole to install a shower and that is when we noticed that the floor drywall was mushy and totally damaged. We had to replace the subfloor and we also had to cut out some ceiling out of our laundry room as it was damaged as well and had small traces of black mold on it (we assumed from the leakage). We haven't replaced the drywall yet in the ceiling so we still have easy access to all of our pipes. This makes me wonder if the smell is reflective at all to any of our previous issues??

Any suggestions? Should I call out a plumber again?

If it only happens when the dryer runs, then it seems like you have an air pressure issue that is pulling the smell into the laundry room. When the dryer exhausts air outside, it must pull air into the laundry room from somewhere. Could there be a plumbing vent that is open in or near the laundry room? Maybe they vented the plumbing inside the wall?

Sheribo, black mold does have a smell but it is not like sewer gas. Are you sure 100% that the odor is sewer gas? I do think you are pulling air into the room when running the dryer. If it is sewer gas then you have a bad trap or no trap on a drain. I think you might be at a place to call in your plumber.

I think you are both right that it is pulling the gas smell into the laundry room from somewhere else. I think at this point I will call a plumber out. Thanks!

Please let us know what the plumber finds is the source of the odor.
Thanks, Bob

Sheribo - did you ever solve this problem? We are having the same issue at our house. Please let me know if you were able to figure it out.

We have had a sewer/gas smell in our laundry room on and off for about a year now. At first we thought it was coming from our new Kenmore front load washing machine as we would get the smell when doing laundry. We had a plumber take a look and he snaked all the drains and said the outdoor pipe had some branches stuck in it. Everything else was fine. No smell for about a month then it came back again. I noticed the smell only starts when we use our electric dryer - not the washing machine! I found this out as one day I put some damp clothes in the dryer (washing machine hadn't been used in days) - and after the dryer was running about 5 minutes the smell started. Any idea what could cause this? Doesn't seem like a plumbing problem but I am not sure. No idea what type of repairman to even call for something like this. I have also noticed that our bathroom sink on the 2nd floor above the laundry room will sometimes have a sewer odor coming from the drain. This will happen maybe once a month and all I do is poor some Drano down and the smell stops. The smell doesn't seem to occur during the same time we are doing laundry.

Did you ever solve the problem?if so how
I have the same problems except the smell comes in my bathroom wich is right behind the wall from laundry room,I hve narrowed it down to the dryer,account that is the only time the smell comes,but I can't figure how it would cause the sewer gas smell when it has nothing to do with the plumbing,if you solved your problem let me know at [email protected]

Have similar problem. Have you figured out what it was? Going on 7 months now with the stink when dryer runs.

TJ

Did you ever figure out what was going on when you use your dryer with the smell?
I have similar issue and it has been going on for 7 months now?

No but I think it may have something to do with thein and out line going into and out of septic tank,also plumber dobled the wax seal under the tolietaccount of tile but anorth plumber has told me that was too much wax should have used only a jumbo seal.I,m going to try that first

Contact me at [email protected] and I'll give you some ideals,I have same problem

Sheribo - did you ever solve this problem? We are having the exact same issue at our house. Please let me know if you were able to figure it out.

Not yet but think maybe the pipe going into and out of septic tank,if you would like contact me on [email protected] and I will tel lyou all that has been done so you don't waste money doing the same thing

Did you ever figure out what was going on when you use your dryer with the smell?
I have similar issue and it has been going on for 7 months now?

No but one thing for sure I can crack the window in the small bath room and then start the dryerand I do not get the smell
We did find the sewer pipe coming from the house about 5 inches under the house was loose account hadn't been glued,we pulled it out and put glue on it and shoved it back in but this didn't help

contact me at [email protected] and i,ll give you some ideals,i have same problem

We live in a condo and are on the lower level on a slab. A few years ago, we noticed bubbling in our ceiling above our bathroom that was just on the other side of our laundry room. The neighbor above had replaced her toilet and they installed the wax ring improperly and it leaked and they did not know until we noticed the bubbling in the ceiling. They replaced the drywall just in our ceiling, but I do not think they cleaned the area above with whatever was coming out of her toilet when she used the rest room and flushed it. The dryer vent goes through a cavity just between our ceiling and the cavity where her toilet leaked. We recently cleaned out our dryer vent after 9 years of living here and got a 5 gallon shop vac full of lint. After that we had a horrible smell of urine or something when we ran our dryer about 15 or 20 minutes after it started.
We investigated for months and borrowed a camera with a cable and opened the casing where the bathroom fan was and put the camera up into the ceiling and looked up into the cavity up under the neighbors floor where the dryer vent went through. We seen black stuff and you could see where the floor was saturated and dried up. I don't think it was ever cleaned. Now that the dryer vent has been cleaned the air flow increased and it is not insulated by the lint and air is able to escape into that space heating up the old urine and feces in there with warm moist air and the crystalized urine has come to life again and the smell, is being forced back into our laundry room where there are cracks from where the vent goes through the wall to go into the dryer. It is nasty... I couldn't sleep last night. Now we don't know who to call and who is responsible for fixing the mess, especially since we are just renting... We had a restoration company come out along with our property manager and showed them the tape and the restoration company believes it is black mold and old urine in the space along with other nasty stinky stuff. Now what to do? This is just my investigation and I hope that it is true and the end is near to getting it fixed so that we do not have to smell this horrid smell throgh the winter with the windows closed.
Just wanted to share my story.
Thanks for listening..

You need a fresh air supply into that room. I have seen this same problem with tightly-sealed homes we have today and always the problem is cured by running a 6" inch flex duct line from attic or eaves into a ceiling vent. You can get all of the parts for about $25 at an HVAC supply house. Another way to do it is to just cut through wall to outside and install a boot in wall connecting to a cover on outside wall to get fresh air in. It should be at least 6" in diameter.

You need a fresh air supply into that room. I have seen this same problem with tightly-sealed homes we have today and always the problem is cured by running a 6" inch flex duct line from attic or eaves into a ceiling vent. You can get all of the parts for about $25 at an HVAC supply house. Another way to do it is to just cut through wall to outside and install a boot in wall connecting to a cover on outside wall to get fresh air in. It should be at least 6" in diameter.

I explained the area in the cavity where the dryer vent is running through. If I could send you a video of what we seen in this cavity and what your thoughts are to your email? Not sure if this is allowed?

Thanks

That would be okay with me.

That would be okay with me.

Okay, I sent the video to your email, did you get it with a link to the video?

It looks pretty bad there. I would clean it all out and replace the Sheetrock in that ceiling, but you still need a vent to keep from drawing moisture in that room. When you exhaust as much air as a dryer does the air has to come from somewhere and if you have a furnace in the house it will draw the air from the flue and kill everyone in the house.

We have the same problem, only when all the doors and windows are shut. So try cracking a window that is closest to the drier, it worked for us, but that is the problem the drier is pulling air from a non-vented trap somewhere in the house or the vent pipe has come apart and is not continuous to the roof.

It is very possible that this one is a case of the pipe coming apart. That is very dangerous.

Using a dryer puts negative pressure in the room. I don't think it's the dryer but you are pulling air in from somewhere, crawl space? Check the drain plumbing again and look for a disconnected drain or vent.

The answers are all good ones, you are pulling air (sewer gas) into the room when the dryer is sucking air into it from outside. You need to seal the drain pipe and be sure that the door on the washer is closed , it will help, but the air / smell can also be drawn in through the washer itself. As for the drain pipe use rags or a sponge , You may be able able to find a rubber plug with you hose size in it a box store to solve the problem. If you can add outside air to the dryer that will solve the problem as well as save you money for have to cool the cold outside. Some dryer vents have and out air hose availabel but probably hard to find in the USA , in Eurpoe they are more common. If you are handy you can craft on yourself. Good luck.