Slight sewer smell when flushing

[jessb_55]

So starting about a month ago I started noticing that when flushing my upstairs toilet I'll get a sewage smell coming from the bowl area. From what I read it sounds like this could be a few things...

1) bad wax seal....which I don't think would apply to me for several reasons because my toilet doesn't use a wax ring as it uses a Fernco wax free toilet seal, the toilet doesn't rock and also if the seal was bad wouldn't you have a sewage smell consistently and not just when you flush?

2) a clog somewhere? I've had no issues with the toilet flushing, nor the sink nor the tub that I believe all use the same stack. Also not gurgling sounds either.

3) So I'm starting to wonder if maybe the toilet has a crack somewhere? I haven't noticed any water on the floor or on the ceiling in the bathroom below.

The toilet is atleast 20 years old but I am on a tight budget and don't just want to replace it just to replace it but I'm starting to wonder if that should be my next step.

Otherwise what other troubleshooting or things I can do in the mean time to try to figure this out?

Thanks in advance

 

[Terry]

If the tub hasn't been used recently, run some water down it. Heck, run some water down it first and then we can start checking things.
It's hard to know why a toilet being flushed would allow sewer gas into the room though. A bad floor seal, normally also has water leakage. How clean is the floor around the bowl? Sometimes I have to become a maid and do some cleaning around mine. Lysol is nice for that.

 

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[jessb_55]

Hi Terry,
Thanks for your response. The tub actually gets used every day. And exactly how you said I would expect a bad floor seal to also show some leakage which there doesn't appear to be any of.

I did end up plugging up the rim jets and filling the overflow with a bleach mix and letting it sit over night and that did seem to help some with the smell but I'm still super stumped.

I would go ahead and replace the wax ring but being a single female resetting a toilet by myself is kind difficult plus I always worry about overtightening the darn thing.

 

[Terry]

The bleach mix sounds like it was a good idea. Looking for smells is always hard.

 

[Jamie2022]

I am having a similar thing happen. Not to hijack this thread, but we are testing a Toto with a 2.5 inch trapway as we had problems with an older low-flush toilet.

With this one we are finding the trapway allows material to pass, but it often stops further down the waste line where there is first a 30 degree bend, or a bit further when there seems to be a 90 degree bend going into the concrete basement floor (bathroom is one level up on first floor). We had not been aware of those bottlenecks with the previous toilet.

When that happens, we have had success with using extra water and dishwashing liquid to clear the obstacle - but when it does move we get a sewer smell coming up from the toilet as the water rushes through.

Is there supposed to be air trapped in the pipe which is making its way back? Or is this an indication of something like a tree root narrowing the pipe? Or improper venting of the stack maybe (it was built recently but maybe something was done incorrectly)?

 

[John Gayewski]

When my toilet clogs my shower trap siphons. It happened to me the other day. It's highly unlikely the toilet is emitting miasma.