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Very bad smell from bathroom

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joeydyi80

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Recently we noticed a bad smell coming from our downstairs bathroom. When we investigated it further it seem that there was some leakage from base of the toilet. So had a plumber come out, took out the toilet, and informed us that the wax ring had failed. So he replaced new wax ring and reinstalled the toilet. The smell never went away and it actually got very bad. The smell gets especially bad when the temperature outside gets very hot. The smell is like a sewer like smell and its very bad. The whole bathroom smells bad and we can pinpoint it coming from base of toilet since we are unable to smell it from sink or bathtub. This bathroom does not have a fan, just a HVAC vent and window. What could the issue be here? Is it some sort of blocked pipe? blocked vent?
 

Geofd

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is the vent pipe on the roof near this bathroom , try closing off the hvac vent for a few days.....is the bathroom used enough to keep all of the traps sealed,is it hot enough there so that the wax ring is failing,i think there are wax rings
made partially of neopreme..what other plumbing is near this bath
 

joeydyi80

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is the vent pipe on the roof near this bathroom , try closing off the hvac vent for a few days.....is the bathroom used enough to keep all of the traps sealed,is it hot enough there so that the wax ring is failing,i think there are wax rings
made partially of neopreme..what other plumbing is near this bath
Bathroom is downstairs and toilet/sink are used maybe 3-4 times a day. There is a shower/tub as well and that has not been used in a quite some time.
 

joeydyi80

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View attachment 25662Try this type of seal and keep the bath tub trap and sink trap full and see what happens.
What do you mean by keeping the bath tub trap and sink trap full? Running the water for a few minutes and then turn it off?

So when the plumber that installed the new wax ring and toilet again did not caulk the base of the toilet all the way. He left a small region in the back of the base uncaulked. After a few days the smell was present day and night as you walked passed the bathroom. So the last few days we tested something and put tape over the small region that was left uncaulked to see if that would make a difference. So right now it is 1pm here on west coast and no smell is present outside or inside the bathroom (and it is already at 100 degrees outside). Yesterday no smell, until late in the afternoon when it was present again. One other thing that I can think about is so far today that toilet has not been used or flushed yet. Yesterday there was no smell until the toilet was used and flushed. So I don't know if that makes a difference or not.
 
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Geofd

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i don't know if this would work but were the caulking is missing hold a piece of tissue paper there and flush a few times if the tissue moves its possible that the seal has been compromised
 

joeydyi80

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i don't know if this would work but were the caulking is missing hold a piece of tissue paper there and flush a few times if the tissue moves its possible that the seal has been compromised
Another thing that we experimented today was that all day today we did not use the downstairs toilet or sink. The weather got pretty hot too around 104 degrees and there was no bad odor up to 9pm when we got back home. The bathroom window as open as normal. Then around 1030pm we used the kitchen sink to wash dishes and used the garbage disposal. Then about 30 minutes after we were done I went to the bathroom to check and I could smell the bad odor again before even entering the bathroom. And when I opened the door sure enough the odor was back. So I don't know what is going on now. Just trying to isolate the issue to one source if I can.
 

Jeff Handy

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You might want to have a smoke test done by pros, they can inject harmless smoke into the drains and the venting system.

It should leak out anyplace that has not got a good seal.
Even behind a wall, under the floor, or in the attic

Sometimes pipes are not glued properly, or they get sawed into, or fittings crack, holes get drilled into drains or vents, toilets don’t seal, lots of places for stink to get out.

Your roof vent pipes might also be clogged with a nest or dead critter.
 

Geofd

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Where is the vent pipe on the roof in relation to the problem bath
Have you tried shutting the window and the HVAC vent , how high is the vent on the roof, have you tried completing the caulking at the base of the toilet
 

joeydyi80

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Where is the vent pipe on the roof in relation to the problem bath
Have you tried shutting the window and the HVAC vent , how high is the vent on the roof, have you tried completing the caulking at the base of the toilet
You might want to have a smoke test done by pros, they can inject harmless smoke into the drains and the venting system.

It should leak out anyplace that has not got a good seal.
Even behind a wall, under the floor, or in the attic

Sometimes pipes are not glued properly, or they get sawed into, or fittings crack, holes get drilled into drains or vents, toilets don’t seal, lots of places for stink to get out.

Your roof vent pipes might also be clogged with a nest or dead critter.
So we tested another theory the last few days. So we sealed the small opening at the base of the toilet with tape for now. The first few days we did not use that bathroom at all and there was no smell. The next day we used it a few times and the sink too and still no smell. So yesterday there was no smell at all day (toilet was flushed few times) until late night. My wife washed the dishes in the kitchen with hot water running for a good while. After she was done she went by the bathroom and noticed the smell was present (even outside the bathroom). When she opened the door sure enough the smell as back. What could this suggest to us on where the smell is coming from? Both the window and HVAC vent were open.

One other thing I might add is that the bath/shower combo in this bathroom has not been used in quite some time (possibly a few years or more). Maybe the water was run a few times in that time frame, but no one has actually used it for a full shower/bath. Could the smell be emitting from this drain by any chance due to lack of use?
 

joeydyi80

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Yes.

Very common problem, unused trap dries out, stink released as sewer gas gets directly out.
So today we ran that shower/tub combo for a while to let the water go down the drain for a while. Then tonight we did the dishes again using hot water in the kitchen and when we checked for the smell in the bathroom it was not present. So was this smell all due to the trap under the tub had dried out and once we ran the water for a bit it fill it up again and no sewer gases coming up from that drain? So if the trap had dried up all this time (and drain was open plug was open too) how come the smell is not present all the time. Why does the smell occur when we are using the kitchen sink especially running the hot water in the sinks there?
 

Jeff Handy

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The smell will get worse when other fixtures or faucets are venting, especially with hot water.

The hot water going down the drain also releases warm vapor going up the vent.
And as that rises it carries sewer stink with it.
Instead of going out the roof, some of that stink was getting out of your dry trap, into your bathroom.
 
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