I've got a basement floor drain that's been giving off a terrible odor as winter winds down. On damp days with temperatures above freezing, the smell gets really bad. I usually drain my dehumidifier into this floor drain during the summer, but I'm not even sure where it leads. I know it goes outside under the concrete, and since I'm on a septic system, there's no connection to public sewer. My theory is that maybe chipmunks have gotten into the drain lines outside, which might be causing the awful smell during the warmer, damp weather. Oh, and the top of the drain is sealed shut, perhaps to keep animals out. Any ideas? Check out the condition of the drain here: https://imgur.com/a/cjSMcCJ.
2 Answers
I’d suggest pouring a couple gallons of water down the drain first. It might fill the trap and help with the smell. A lot of floor drains have traps similar to sinks, and sometimes the water in them evaporates, especially during winter months. When I tried this, it helped a bit for me!
It sounds like your floor drain likely connects to your septic system. During winter, the water can dry up in the trap. Using your dehumidifier keeps it filled in the summer, but you should test it out. Some people even recommend adding a little vegetable oil on top of the water to help prevent evaporation and keep smells at bay. Mineral oil is a good option too for trap maintenance if it doesn't get much use.
Yeah, mineral oil is great for traps that don't get a lot of action!
Just poured 2 gallons down there and it seemed to help a little! It's funny because I could hear water flowing before I even dumped it, so it must be connected to a perimeter or sub-slab drain. Strange situation!