Musty toilet water/mildew smell from downstairs bathroom

[Sunday Gladiator]

Hello,

Just joined this forum. I registered mainly because I was inspired by this thread here -

https://terrylove.com/forums/index....d-wax-ring-twice-still-have-odor.57641/page-2

I've run into a similar issue with my downstairs guest bathroom, which is just a toilet and sink next to it. The issue has persisted for a full year now - best way to describe it is a pervasive musty, toilety, mildewy water smell coming from this bathroom. Not sewage smell, but a musty old water smell.

We've stopped using the toilet and sink for several weeks now. Whenever we run the showers or sinks in the upstairs bathroom, the smell kicks in (my wife smells it the strongest). The smell then comes from the upstairs bathrooms, and emanates from the downstairs bathroom too.

Here's what's been done thus far, and the timeline of attempted fixes -

> Checked all traps in downstairs sinks, including this bathroom. Cleaned out traps, made sure water was in p traps than air for one week. Smell continued.

> Replaced the Kohler toilet with the Toto Drake® II Two-Piece Toilet, 1.28 GPF. Wax ring replaced in the installation. Smell continued.

> Ran cameras in our sewer line from outside clean out. Ran camera all throughout the lateral line, that goes past our downstairs bathroom, lateral pipe then makes a turn under living room, then down all the way to the street level sewer line. All clear. But... minor 'calcification' in the pipe just behind where the lateral line goes past the downstairs bathroom. Sewer line camera tech said it's minor, and in his opinion, not a cause for concern or smell. Decided not to flush lateral pipe. Smell continued.

> Opened up walls in downstairs bathroom to expose vent pipes. Ran smoke test from outside clean out to check vent pipes. No sign of smoke from vent pipes, both at toilet and downstairs sink. Nor upstairs. Nothing. But... after capping the final 3rd vent pipe in attic, a tiny funnel of smoke appeared at the edge of the closet flange in downstairs bathroom's toilet! The plumber then stuffed rags tight and deep into the pipe past the flange to check to see if there was a crack or leak past the concrete and towards the lateral line. Ran smoke test again. No sign of smoke. New closet flange put in and sealed. Rags removed. Ran smoke test again. No smoke! Toto toilet re-installed.

> Next day, no smell! Hooray. Toilet used and sink used.

> Day two, smell came creeping back, but not coming from toilet. This time same ol musty/mildewy smell coming from downstairs sink. Proceeded to stop using downstairs sink and toilet. Smell continued.

> From day three to today - 2 weeks later. Smell continues in downstairs bathroom, and upstairs whenever showers or sinks are used. A musty/mildewy water smell coming from downstair bathroom sink.

Next steps I am thinking -

> Have plumber run enzyme based cleaner (not Drano!) down into ALL showers and sinks upstairs and downstairs.

> Remove downstairs bathroom toilet and have Sewer Line Camera tech run a camera through toilet and to the lateral line to run a leak detection. Try and check for any cracks in pipe (I was told this was a difficult detection, only leaks can be detected).

That's where I am today. Quite the short story saga. Any further insights or investigations I should do beyond the above, I'm all ears!

Thanks, Parker

 

[Reach4]

Cover the suspect toilet with a cheap plastic drop cloth. Tape the edges to the floor just around the base.

See if the smell changes much. Lift an edge, and sniff under the plastic. Is the smell much stronger under the plastic?

Consider isolating the lavatory or any other suspect area for sniff testing by your wife.

 

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[Sunday Gladiator]

Cover the suspect toilet with a cheap plastic drop cloth. Tape the edges to the floor just around the base.

See if the smell changes much. Lift an edge, and sniff under the plastic. Is the smell much stronger under the plastic?

Consider isolating the lavatory or any other suspect area for sniff testing by your wife.

That's a good suggestion. However my wife just clarified to me that the smell is not actually coming from the downstairs toilet itself. It's a pervasive musty/mildewy water smell all throughout the house. Exacerbated whenever the downstairs toilet or sink is used.

That would suggest, albeit in my novice plumbing opinion, a vent pipe issue. However, smoke test was run throughout all vent pipes, and no sign of leakage. Only sign was coming from downstairs toilet flange, which was replaced, smoke test ran again, and no further sign of leak.

 

[Reach4]

I am thinking peppermint test. Does the smell appear quickly, or is it long delayed?

Cheaper than a smoke test. But whoever handles the peppermint must not come back into the house after pouring.

Another test is to block the big soil pipe exiting the house with a test ball. Put water in at least until the floor drain is full to the floor level. See if the water level falls indicate a leak below the floor.

I am not a plumber. I have never done any of these tests.

 

[Sylvan]

"I am thinking peppermint test. "

Suggesting a peppermint test without knowing exactly how it is performed is not the best advice

Regarding a "smoke test" not a great idea if a vent or waste pipe inside the walls has a defect

Has anyone suggested a hydrostatic test?

To do a proper peppermint test

You will need the following

10 quarts of boiled water. and about two ounces of the peppermint oil and have someone pour it down a vent terminal and cap the vent pipe until the test is completed

The person handing the oil of peppermint should NOT enter the structure until the test is over

Then several people inside should walk around sniffing for the peppermint odor

 

[Sunday Gladiator]

Thank you for those peppermint and hydrostatic suggestions. Never heard of them till now. After I go through my next steps with the plumber on Monday, I'll inquire about those options and their experiences with them.

 

[Sunday Gladiator]

Forgot to address Reach4's question...

It's a few seconds delay (after downstairs bathroom sink or toilet is used), it will smell in the air and into the other rooms throughout house. In the downstairs sink, it lasts for days upstairs and downstairs. If one does not touch the downstairs bathroom sink, the smell is very faint there in bathroom and upstairs.

 

[Sunday Gladiator]

Thought I'd post a quick update.

The smell has been isolated to the kitchen cleanout, and the pipe goes right to our downstairs bathroom. Running a sewer camera, all sorts of gunk was spotted down that cleanout. Plumber came out to jet it, yet the smell came back a few days later.

Here's the bizarre part – when I leave the kitchen cleanout open (which is outside of our patio), the smell inside house goes away. When I close the cleanout, smell comes back.

Which makes me think it's a vent pipe issue. Plumber comes back, runs smoke test on all vent pipes - all vents are working fine.

Now we're stuck to leaving that cleanout open outside, and watery crud from the kitchen drips out of it. Which is gross as I have to leave a bowl outside to catch all this kitchen run off.

But no smell inside the house! I'll take dumping a bowl of kitchen waste once a day than having the wife complain about the smell every day.

Just odd, as we've owned this house close to fifteen years, and it's the first it's ever happened.

Further thoughts from the plumbing brain trust here welcomed. Otherwise I'll continue with the frontier method using the bowl.