Our septic backed up a couple of weeks ago. It ended up being a clog, which the septic company removed. Ever since then, you can smell a sewage smell in the basement, which, of course, is coming up through the house, now that the furnace is on.

We traced the smell to the drainage hole in the basement floor. Any ideas on what this could be?

Our septic backed up a couple of weeks ago. It ended up being a clog, which the septic company removed. Ever since then, you can smell a sewage smell in the basement, which, of course, is coming up through the house, now that the furnace is on.

We traced the smell to the drainage hole in the basement floor. Any ideas on what this could be?
Your floor drain should have a trap, but some time when it is not used the water will evaporate. Try putting about a gallon of water down it and see if this don't help.

If the floor drain's unused pour a quart of anti-freeze or motor oil down the opening. This will prevent evaporation and loss of the trap seal. Good luck, Tom

If the floor drain's unused pour a quart of anti-freeze or motor oil down the opening. This will prevent evaporation and loss of the trap seal. Good luck, Tom

Thank you both, for your answers. It is a used drain.

The septic company just left, there's no leak, septic is working fine. He didn't really have an answer for us.

So, we poured a few gallons of water down the vent, and I watched debris move through the pipe. We're hoping this was part of the problem (vent being clogged) and it will aleviate it.

His suggestion was to put chlorine tablets down the drain, which we did. We'd already poured bleach down it, to no avail.

It's very frustrating. While I'm glad there's nothing major, I still don't know why it stinks and there HAS to be a connection between the clog we had a couple of weeks ago and the smell now.

Well, the water down the vent pipe didn't work. It still stinks.

I watched debris move through the sic,(vent)pipe. We're hoping this was part of the problem (vent being clogged) and it will aleviate it.
Even if it didn't clear up the smell there should still be no "debris" in the vent. Pouring water down it won't clear it. It must be snaked from the roof vent.

Well, the water down the vent pipe didn't work. It still stinks. What still stinks? The floor drain? When you flush or drain do any of the fixtures make a sound? If there were a partial clog in the line to the septic tank and you had back pressure from it the backpressure could send a bubble of sewer gas back through the first fixture,( your floor drain) that it came to. Did the plumber snake from the house to the septic tank to be sure the line was completely clear? Let me know, Tom

The septic guy just checked the septic, the drain that smells, isn't even part of the septic. It's a separate drain, so no, he didn't snake it. He didn't snake anything.

I haven't noticed any kind of sound when flushing, or doing laundry. It's just weird. We have a snake, should we try snaking the drain in the floor ourselves? And, the vent pipe?

I've got an actual plumber coming next week, for a separate issue, so I could ask him to check, but if this is something we could do ourselves to save money, I'd rather do it that way.

Let's first find out if that floor drain even has a trap. Your man should have checked that and informed you. Put a stick or rod down the floor drain. It should come back with at least 2 or 3 inches of water on it. If not then it's untrapped and you have located the cause of the odor. Let me know. Tom