The toilet has been off the closet flange for a week, and I have not put
anything in the drain pipe to prevent sewer gases from drifting up into
the bathroom. Yet I don't smell any, and my smelling is excellent. From
the plumbing diagrams on the web, there are no traps other than the one
in the toilet. Should I be concerned that there is a blockage further
down the drain?
The house is 15 years old and built on a slab.
> The toilet has been off the closet flange for a week, and I have not put
If I had to guess, I'd guess it was because the vent stack that toilet
empties into is on the downwind side of your house.
I'm thinking that if the wind across North America is generally in a
west to east direction, if your vent stack opens up on the east side of
your roof, the wind blowing over your roof could be causing an low
pressure area on the east side of the roof, possibly causing air to be
sucked up the vent stack.
Test the idea. Light a cotton shoe lace until it's burning under it's
own steam, and then blow out the flame so that the cotton is smoldering,
releasing a steady stream of smoke as it burns. You now have a poor
man's smoke pencil. Hold the smoldering end of the shoe lace over your
floor flange (or what's left of it) and see if the smoke gets sucked
into the toilet waste pipe or blown out of it. If it gets blown out,
then it could be that the prevailing wind is pushing air down your vent
stack, and preventing sewer gas from coming up. If it gets sucked into
the toilet waste pipe, it's probably due to the wind blowing over your
Interesting theory, but the toilet has been off the flange for a week.
During that time the winds have varied from zero to fairly high. I can't
state that the winds/gusts have always been from the same direction.
I used a length of twine. (Shoelaces still packed somewhere in my moving
boxes.) Produced black smoke with the flame present, then white after I
blew the flame out. The smoke rose, but that's its natural tendency
anyway. It didn't rise fast when I held the string over the opening.
I then cut a thin strip, 1/4" by 3" of single-ply facial tissue and held
it over the opening. Wasn't sucked down or blown upward.
I dumped about a gallon of water down the drain. It simply went away. If
there is a blockage farther down the drain pipe, this test wouldn't
detect it. Maybe I should run a garden hose down the drain for five minutes.
Rather than worrying about a blockage in the drain line, I think I'd take that as an indication that
there is *not* a blockage in your vent stack, and that the sewer line is venting properly through
it. If you like, go up on the roof on a calm day and sniff the top of the vent stack. I bet you smell
sewer gases there!
So, the smoke test shows there's no flow of air either into or out of
the toilet drain pipe. That is the reason why there's no smell. Now,
we have to ask ourselves whether there should or shouldn't be air flow
into or out of that toilet drain pipe.
I don't know the answer to that question, but I do know that a 7-11
Super Big Gulp cup is the perfect size to act as a stopper on a 4 inch
toilet drain pipe IF you wanted to stopper it up.
I talked to a worker, years ago. We were having
a candid moment, after I made a mistayke on
one of his machines. He tells me that a foam
coffee cup works nicely. He says that if you
leave the foam cup in, and put the toilet back,
that the water overflows the bowl and goes on
Christopher A. Young
Learn about Jesus
Just be happy that water goes down and gasses don't seem to be coming out.
On a slab, unless you want to rent a sewer camera or hire a plumber that has one, all we can do is speculate, and there are bigger problems than "no smell" that are on this site.
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