We moved into a house with a sewer gas smell. We did find 3 open sewer drains that we capped. The odor went away for a week and now is back. It is worse when the heat is on and is so bad we can't turn on the heat. It is pulling the smell from our basement but we can't locate it. We checked all drains and the traps are working fine and do not smell. We do have city sewer and there is a large holding tank about 100 yards from our house. Could that be the problem? We also had a mold and a wildlife company out and they couldn't find anything.

What plumbing fixtures are there in the basement ? Any floor drains ?

Furnace on one side (that side doesn't smell) and the other is water softner, water heater, washer and dryer. 6ft ceiling and about a 8 X18ft space. There is a crawl space but not including in the 8 X 18ft space (guessing space size).

A holding tank with city sewer, very unusual. Can you tell us more about the tank and its function? Also tell us more about the 3 capped sewer drains, what were they once connected to? Do you have an attic and can you see your vent stack reaching up through the roof line?

Yes, a holding tank for 3 cities. Then once it gets full it is flushed?
That is what the city said when I had them come out. The plumber located 3 exposed sewer drains that were once in use? Our house was bulit in 1924 and they were just open. I am guessing they were connected to a different type of drainage (maybe a septic tanka t one time?). The plumber did go on the roof and run the water hose down and it appeared to be clear and offer no leaks.. but will look again. What are my other options? What about having the lines cleaned or hiring someone to bring a smoke machine in? I want to try to elminate all my options before I go to the city.

Look in the crawl space. See if there is any additional uncapped sewer pipe. Also, that washer: does it have trap installed ?

"Yes, a holding tank for 3 cities" never heard of anything like this, where are you located?

Also, if this room is in the basement - how is it being pumped up and out of the house ? Sewer ejector ?

You can't crawl in there because it is to small but we can double check. That is where we found 2 open pipes.washer doesn't have a trap on it but it drains to the tub when does have one on it. When water softner is running the smell goes away & it drains to tub to.

We are in Long Lake, MN. They put in a new road about 6 years ago and installed a new sewer system and a holding tank? Thank you for your help. How can I tell if it is a city problem or my problem. I just want the smell to go away.

Thanks Milo. I am guessing it is being pumped out to my main sewer drain which I do believe in the basement? Sorry I am not that good at describing things but I do know it goes out form my house

Most likely it is your problem. If you had 3 open drains - then there is a chance there may be 4th one.

Regarding that Sewer Ejector: do you know where it is located ? Look for it and let us know what it looks like - or even better, snap a picture of it and post it...

I hope we can find it. The plumber is coming out again. Would you sugguest a smoke machine?

Milo... I will check when the plumber is there and take a picture of it. Thanks

It depends how experienced the plumber is. Good plumber will find open pipe without use of smoke machine.

Good answer. I think he is pretty good. Will let you know. Again, thanks