Sewer gas smell in toilet bowl

[Tom Anderson]

I have a downstairs bath (on slab) where the toilet began emitting a sewer gas smell about 6 months ago. We've been in the house for 28 years. Sink and shower does not smell...just he toilet from inside the bowl. All 3 drain fine into septic tank. Here's what I've tried:

1. Made sure all P-traps were full
2. Pulled toilet and installed new wax ring
3. Got up on roof and ran a hose (with a pipe bladder) into the vent and ran water for 10 minutes. Did not appear to be any blockage. Can clearly hear toilet flush from vent pipe on roof.
4. Covered the bowl tightly with Saran Wrap and smell in the room went away.

Any suggestions as to what to try next?

 

[CountryBumkin]

Clean the bowl
Seriously, the wax ring and water in the bowl prevent sewer gas from leaking in. It could be that the water itself has a high level of sulfur in it (my FL well water certainly does). Are you on city water or a well? Do you have any sort of water treatment system/equipment?

 

[Sponsor]

 

[Reach4]

Your Saran Wrap test is definitive. If the water itself does not have the smell, which I think you would have detected in other fixtures, I would replace the toilet. Most new toilets, despite using less water than they did in 1989, work better. I would go for a 1.6 GPF myself, unless you are near a dry area. 1.28 GPF flushes usually perform well also.

I am glad you did not let guests use that bathroom during the test period. ;-)

 

[Tom Anderson]

The water is not the problem as none of the other fixtures (including 3 other toilets) in the house have this problem. Just to make sure, I took some of the water out of the toilet and put into a bowl = no smell. I did fail to mention in my original post that the toilet was replaced about 6 years ago when we remodeled the bathroom...so it does have one of the newer 1.6GPF units.

 

[CountryBumkin]

If you put a little chlorine/bleach in the tank, does the smell go away?

When you replaced the wax ring, did you inspect the closet flange and surrounding area for signs of staining/damage?

Could there be some "waste" built up under the toilet (around the toilet horn or in the cavities on the underside) that you failed to clean out or notice when you removed the toilet and replaced the wax?

 

[Gary Swart]

I think the wax ring has been compromised. Maybe from agresive plunging, but any other movement of the toilet would break the seal. It would not cause a water leak. That said, it might well be time for a new Toto.

 

[Tom Anderson]

Probably the least costly next step would be to try a new wax ring. Any thoughts on the new "Wax Free" rings?

 

[CountryBumkin]

I like the Sani-Seal.
I have used it a couple of times now (but I'm not in the business, so the opportunities don't come often). But on my last tile job/toilet install I couldn't get the Sani-Seal to compress enough over a closet flange that was sticking up a little above the finished floor, so I had to resort to using a wax ring on that one. They work great where the flange is even or slightly below the finished floor.

 

[Reach4]

so it does have one of the newer 1.6GPF units.

So the choices that I see that fit the description are that the toilet is defective, or something stinky is growing in that toilet base. You have not said whether you are using chlorinated city water or well water.

If you slowly add an extra quart of water to the bowl, does the water level in the toilet stay higher (than it was before pouring) for a minute? How high does the water end up compared to the top of the exit hole that you see?

 

[Twila]

Mr. Anderson, Did you every resolve your problem? I have the exact same problem with one downstairs toilet
on a slab. This house is 5 years old and I noticed it shortly after moving in a year ago. This toilet is the closest
one to the septic tank. I have tried cleaning the tank and bowl with clorox. Replaced the wax ring with a new
wax free ring. But the smell remains. Also I have shims under the toilet to prevent movement. What else
could I do?

 

[Reach4]

Replaced the wax ring with a new
wax free ring. But the smell remains. Also I have shims under the toilet to prevent movement. What else
could I do?

Try the Saran Wrap test. Maybe write on the Saran Wrap with marker so that a potential user will see the plastic in place.

 

[Twila]

Ok I will try that tomorrow.

 

[Jadnashua]

Is there any perceptible rocking of the toilet if you try to move it? If so, you need a new wax ring and shims. Once a toilet rocks one way, it compresses the wax, and if it then rocks back the other way, it leaves a gap. You must stop any tendency for it to rock. If the smells are coming from underneath the toilet that's the most likely place, but you can also get problems if you have not sealed around the base of the toilet to the floor...crud can get underneath and be nearly impossible to clean up unless you pull the toilet, but it will just happen again unless you seal that joint.

 

[Twila]

I tried the saran wrap for 24 hours and then 24 hours after removing it the smell was back. It seems like after it
had been used again several times the smell returned. What does this mean? BTW Jim, the toilet is not rocking
because I placed shims under it after installing the no wax ring.

 

[Ruben11]

Twila, were you able the fix the problem?
I can smell something from toilet in my newly finished basement. I replaced the wax ring. There were nothing wrong there, dry and clean.

 

[Ruben11]

I have a downstairs bath (on slab) where the toilet began emitting a sewer gas smell about 6 months ago. We've been in the house for 28 years. Sink and shower does not smell...just he toilet from inside the bowl. All 3 drain fine into septic tank. Here's what I've tried:

1. Made sure all P-traps were full
2. Pulled toilet and installed new wax ring
3. Got up on roof and ran a hose (with a pipe bladder) into the vent and ran water for 10 minutes. Did not appear to be any blockage. Can clearly hear toilet flush from vent pipe on roof.
4. Covered the bowl tightly with Saran Wrap and smell in the room went away.

Any suggestions as to what to try next?

I did everything except #3.

Curious if You can fix this

 

[Reach4]

I did everything except #3.

Curious if You can fix this

If the water in the bowl has been filled by the refill as much as it can go, then your toilet is defective. Replace it. Since the saran wrap stopped the smell, the water seal was not sufficient to stop the smell. So the toilet must be letting the water drain out somehow.

If the water has not been filled in the bowl to the level that the bowl can sustain, check that the refill hose in the tank is pointing down the drain. If it is, adjust the fill valve for more refill water. If no refill increase is available, replace the fill valve.

 

[mbmsv]

If you slowly add an extra quart of water to the bowl, does the water level in the toilet stay higher (than it was before pouring) for a minute? How high does the water end up compared to the top of the exit hole that you see?

If the water in the bowl has been filled by the refill as much as it can go, then your toilet is defective. Replace it. Since the saran wrap stopped the smell, the water seal was not sufficient to stop the smell. So the toilet must be letting the water drain out somehow.

If the water has not been filled in the bowl to the level that the bowl can sustain, check that the refill hose in the tank is pointing down the drain. If it is, adjust the fill valve for more refill water. If no refill increase is available, replace the fill valve.

Hi Reach4,

I have exactly the same problem and I do believe the problem is the toilet itself but I can't see anything wrong with it. Could you please explain your test with filling the bowl one more time? I read it several times but I am not sure I understand what I should be looking at. Thanks!

 

[Reach4]

I have exactly the same problem and I do believe the problem is the toilet itself but I can't see anything wrong with it. Could you please explain your test with filling the bowl one more time?

A bowl can only hold so much before water goes over a hidden weir/dam inside the toilet. Adding more water and waiting a minute can tell you what that water level is.

The refill tube on the fill valve squirts water into the overflow tube into the tank. That water replaces the water in the bowl that flushed away. The refilling should bring the water level to that maximum level discussed in the first paragraph. Squirting more water than is needed to bring the bowl water to that limiting level does not help.

If the refill was not enough, the next flush is starting out with a deficit of water. That makes the flush weaker.

Now if you are getting a smell, that would suggest that the water fill is not up to the weir, it may not even be up to the top of the big hole in the bowl. So air can pass under. If that is the case, having the refill add more water could cure the problem. Rarely the toilet is cracked letting the water drop even lower than the weir level. Letting the toilet bowl dry out can cause a shortage of water also.

 

[mbmsv]

A bowl can only hold so much before water goes over a hidden weir/dam inside the toilet. Adding more water and waiting a minute can tell you what that water level is.

The refill tube on the fill valve squirts water into the overflow tube into the tank. That water replaces the water in the bowl that flushed away. The refilling should bring the water level to that maximum level discussed in the first paragraph. Squirting more water than is needed to bring the bowl water to that limiting level does not help.

If the refill was not enough, the next flush is starting out with a deficit of water. That makes the flush weaker.

Now if you are getting a smell, that would suggest that the water fill is not up to the weir, it may not even be up to the top of the big hole in the bowl. So air can pass under. If that is the case, having the refill add more water could cure the problem. Rarely the toilet is cracked letting the water drop even lower than the weir level. Letting the toilet bowl dry out can cause a shortage of water also.

Thank you.