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.

I can't believe it would be the dryer. Now if you are getting form upstairs drain it has to be a plumbing issue. Has anyone ran a snake down the vent pipe on the roof? If a plumber as checked the drain I believe I would have someone snake the roof vent.

Yes the vent pipe on the roof as well as the basement floor drain was snaked. Right after this was done we did laundry and there was no smell. Within a couple weeks the smell was back!

Seal off the area where the washer drain hose gose into the drain pipe and see if that makes a differece

Someone else advised that I try sealing off the drain pipe as well. We did that 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.

Any suggestions? Should I call out a plumber again?

Have you removed the vent hose and checked/cleaned out the vent to the outside? Sometimes small animals/rodents can get inside and make a nest.

How about a dead animal in the dryer vent?

The dryer vent is only about 2 feet long... it is the exterior wall that the dryer sits against... so not far to go - nothing blocking it.

We had experienced a sewer gas smell in our old house and thought it was from the toilet or washing machine. We are now in a new house and after 5 months here, the smell is back, and it is definitely coming from our Kenmore front load 90 series dryer. What can be done to stop it?

OK here is what is likely happening. The dryer blows hot exhaust out its vent, that creates a slip vacuum in the room and make up air needs to enter the room to let the pressure equalize. It sounds like some of that make up air is coming from your sewer line. Sheri, I'm the guy who said to test with Saran wrap a few weeks back. Tell us again what happened when you put the temporary wrap on the vent. Is there a toilet in the immediate area, many sewer gas leaks are traced to bad wax toilet seals.

Pull back the rubber boot inside the front and clean it out. Water sometimes sits there and causes mildew oder. Using a small amount to clean will help

We tried the saran wrap and that made no difference. I have had lots of suggestions from people on what to try and nothing has work. We recently tried taping all of our drains (sink/shower etc etc). The test was to see if all the drains were sealed and there was no air allowed in- would there still be the smell? If there was no smell then we were going to one by one untape a drain until the smell started again. We had hoped this would pinpoint where the problem was. BUT... unfortunately - we taped all the drains and the smell still came. I agree with your theory about the air being brought into the room to equalize. I tested by venting my dryer into the room (and blocked the outside vent) and there was no smell. So now our problem is finding out where the smell is coming from. We think it may be a cracked pipe somewhere as it doesn't appear to be from a drain. There is a toilet in the room ride beside the laundry room. So that is something else we can check out. I don't understand what Candykitten means by "rubber boot". We tried calling a few different plumbers out. But as soon as I explain what is going on they say they have no idea what it could be and either say they don't think they can do anything or they say it could take a LONG time to figure out (expensive).. and they may have to start knocking walls down! We also live on a farm so a few plumbers didn't even want to come! So that is our last resort. Still trying to figure this out on our own.