Sewers
Sewer gas smell when running attic fan?
When we run our attic fan (also called whole house fan) we get this ghastly smell coming up from our finished basement. It 'seems' to be coming from the bathroom where we removed a shower. We put a small raised platform over the old shower drain-I thought this might be the problem, removed a board, poured bleach down the drain, but it didn't work. the smell is so bad in the basement that you literally get sick to your stomach and it isn't the best upstairs either. Does anyone have any ideas on what this might be caused by? It did not do this when we first moved in and didn't do it right after we removed the shower. my dh seems to think that the p-trap is dry? others i've asked think say they don't think that sounds right? Thanks so much in advance!
Public Comments
- might be a dead animal, like a squirrel. that can smell really bad.
- You may have cut open a vent pipe in the wall
- A dry p-trap makes sense. Essentially with a dry p-trap there is nothing between your house and the sewer. Try pouring enough water down the drain to fill up the trap, and then try your fan again. If the smell goes away you'll know that you've isolated the problem.
- If you did not seal off the drain in the basement, you need to do so, first to stop this odor from coming in, second, to prevent any overflow from a sewer line backup from coming in. Seal the drain so it can't leak air or water.
- Scout is right! If you removed the shower, you should have capped off the drain. This will eliminate any possibility of sewage backing up into the house, and if it is capped off, it won't matter that the trap dries out. Also, look around where the air is drawn into the house, and see if any vent pipes are located close to the fresh air intake. If there is a vent in close proximity, you might have to extend the vent away from the fan. Good luck!
- You have mis-diagnosed the problem. Id say its not sewer gas at all. You have moisture behind those walls in the basement that has caused some kind of mold or mildew to form and that is permeating upward to the first floor once you put on that attic fan due to a drop in pressure on the first floor. There are many homes with finished basements in which furing strips are directly nailed to the cement walls and a sheet of drywall or paneling placed over. What happens here sometimes is a crack in the block or cement will allow a small amount of unnoticable water to enter and that will cause a smell after a while. These are difficult to pin point under which paneling they occur but I would say you have something like this happening and not some kind of a sewer gas. Sometimes its very difficult to get a basement to be odor free. The purchase of an Electrostatic Total House air filter on the furnace and AC does very well as that filter removes mold, mildew, bacteria, viruses and YES odor.
