Sink Flange Smell

[Dvid]

Our master bathroom sinks smelling bad for a while. Almost like sulfur, but just found when you cut the water on.

-Not the water which sampled smells fine hot and cold by itself, so not hot water heater.
-P-trap always has water in it, never dry.
-Ran a boroscope through the p-trap up the back assembly. Not too bad in terms of build up, but...
-Removed, cleaned the p-trap, as well as the popup, and the tube for the flange and the tailpiece.
-Have cleaned the overflow hole and reservoir area in the back of the sink with a spray bottle and brush. Nose up to that hole I don't smell sulfur.
-We've tested the water. Only issue is hardness for which we have a softener. Testing the water shows it is soft. We do have higher Manganese.

Noticed the original plumber filled these four holes in the sink flange (picture) with putty which was starting to deteriorate. A handyman friend told me that was extra putty when the sink was installed and it cold be removed especially since one of them connects to the overflow. So I took out as much putty as I could with tweezers, but there are still some small chunks in there time to time swimming around

These four flange holes hold water and if I dip a Q-tip in those hole it smells like the rotten sulfur smell. Little chunks of putty I get out smell like it. Guessing every time I activate the sink water swishes in there and kicks up odor?

So, should these holes be filled with putty to prevent standing water from being in there?

Any other reason this flange would smell so bad? We do get an orangish build up that we clean every few months beyond regular sink cleaning.

Anything I can try? Thanks!

 

[wwhitney]

Those 4 holes are how water that makes it to the overflow can get out into the drain. So blocking them is not a good long term solution. If you pour water into the overflow hole directly, you should see that water will flow out one or more of the holes. Blocking those holes temporarily would be a method to fill your overflow passage with a sanitizer, if that is desired (no opinion on whether that is useful).

You mentioned that behind the holes there is standing water. That is something that I have always wondered about this design of lavatories--the overflow passage connects to a region around this drain which has a certain lowest elevation. Ideally the lowest elevation of the holes would match that elevation, so that no water could accumulate (other than due to surface tension). But if for some reason there is a height mismatch so that the bottom of the holes is a little higher, then whenever water gets into the overflow, some accumulation will remain at the bottom that can't drain out the holes, and it can only leave by eventually evaporating. [Along with the question of whether normally draining water might wrap into the holes via surface tension and still accumulate due to the possible height difference.]

I bring this up mostly by way of relative background, and to see what those with more hands on experience have to say about it.

Cheers, Wayne

 

[Sponsor]

 

[Reach4]

city water or your own well?

Try closing the stopper. Fill the sink. Add 2 TSP to 1/4 cup of chlorine bleach. Slowly add water to let the treated water dribble thru the overflow path.

For your holes, you could file the bottom of the holes to let standing water clear.

 

[Dvid]

Those 4 holes are how water that makes it to the overflow can get out into the drain. So blocking them is not a good long term solution. If you pour water into the overflow hole directly, you should see that water will flow out one or more of the holes. Blocking those holes temporarily would be a method to fill your overflow passage with a sanitizer, if that is desired (no opinion on whether that is useful).

You mentioned that behind the holes there is standing water. That is something that I have always wondered about this design of lavatories--the overflow passage connects to a region around this drain which has a certain lowest elevation. Ideally the lowest elevation of the holes would match that elevation, so that no water could accumulate (other than due to surface tension). But if for some reason there is a height mismatch so that the bottom of the holes is a little higher, then whenever water gets into the overflow, some accumulation will remain at the bottom that can't drain out the holes, and it can only leave by eventually evaporating. [Along with the question of whether normally draining water might wrap into the holes via surface tension and still accumulate due to the possible height difference.]

I bring this up mostly by way of relative background, and to see what those with more hands on experience have to say about it.

Cheers, Wayne

I like this idea of temporarily blocking the flange hole(s) to sanitize the overflow reservoir. I'm not sure that is the issue though. I bought a cheap $1 squeeze bottle like for ketchup and fill it up with vinegar or cleaner and squeeze into the overflow hole in the back of the sink. I can see it fill and pour out in the flange. I've also taken a brush into the overflow hole on the back of the sink and scrubbed around.

For some reason the stink comes back within a few days.

 

[Dvid]

city water or your own well?

Try closing the stopper. Fill the sink. Add 2 TSP to 1/4 cup of chlorine bleach. Slowly add water to let the treated water dribble thru the overflow path.

For your holes, you could file the bottom of the holes to let standing water clear.

We are on well water with a septic system and are always told to avoid adding bleach because it hurts the septic bacteria breaking down material.

I just mentioned in another reply I bought a cheap $1 plastic squeeze bottle I fill with cleaner or vinegar and can squirt aggressively into the sink overflow hole and flange holes. It helps, but the smell comes back.
Filing down the flange holes. In theory that sounds good, and would relieve some water build up but not all as there appears to be a dip in the porcelain that goes below the metal. Not sure how I'd even file the flange holes down. Maybe you are saying to remove the flange and do that. Might be above my homeowner ability.

Guess it was good I took the putty out. It's amazing, even after squeeze bottling those holes may times there are still chunks of putty in there. They smell terrible.

Thanks for al the ideas.

 

[wwhitney]

The putty was likely left over from the original drain install, excess putty gets squeezed out both into the basin and downward, and it could be enough to inadvertently block the holes.

As far as keeping bleach from your septic, you have the option to temporarily remove the p-trap and stick a bucket under the tailpiece to catch the bleach solution.

Cheers, Wayne

 

[Dvid]

The putty was likely left over from the original drain install, excess putty gets squeezed out both into the basin and downward, and it could be enough to inadvertently block the holes.

As far as keeping bleach from your septic, you have the option to temporarily remove the p-trap and stick a bucket under the tailpiece to catch the bleach solution.

Cheers, Wayne

True. Or I would think that squeeze bottle with vinegar would be about as 80-90% effective.

For the one sink I already cleaned the p-trap (nasty, smelly job) I might leave well alone. For the other side) my wife's maybe I will do that when I clean the p-trap there.
I should have added that. When I cleaned the p-trap on my sink the black pipe going out didn't smell great. Not much I could do there. This past Summer and Fall I purchased a garden hose bladder and put it down the sink flange and flushed pretty aggressively to break up anything I could. I can't really clean that drain pipe better than that. I tried to get the scope to go back there but it wouldn't go past the back of the p-trap. I can try it again on my wife's side when the p-trap is off. I HATE cleaning those things.

 

[Reach4]

You could pull the trap apart. Seal the tailpiece with a plastic sheet/bag held in place with a rubber band. Fill the bowl above the drain holes.

If you first drop the pH with vinegar, and then add chlorine bleach, you can make your solution in that blocked sink very effective.

While the septic can handle some chlorine bleach, you could drain the tail piece into a bucket.

 

[wwhitney]

If you first drop the pH with vinegar, and then add chlorine bleach, you can make your solution in that blocked sink very effective.

While also possibly releasing chlorine gas, a chemical weapon.

Don't ever do this. While someone very experienced could carefully control the pH throughout the process to avoid releasing chlorine gas, the pH of vinegar alone is enough to liberate chlorine gas from bleach. The risk/reward ratio is way too high.

Cheers, Wayne

 

[Robert Gift]

Our master bathroom sinks smelling bad for a while. Almost like sulfur, but just found when you cut the water on.

-Not the water which sampled smells fine hot and cold by itself, so not hot water heater.
-P-trap always has water in it, never dry.
-Ran a boroscope through the p-trap up the back assembly. Not too bad in terms of build up, but...
-Removed, cleaned the p-trap, as well as the popup, and the tube for the flange and the tailpiece.
-Have cleaned the overflow hole and reservoir area in the back of the sink with a spray bottle and brush. Nose up to that hole I don't smell sulfur.
-We've tested the water. Only issue is hardness for which we have a softener. Testing the water shows it is soft. We do have higher Manganese.

Noticed the original plumber filled these four holes in the sink flange (picture) with putty which was starting to deteriorate. A handyman friend told me that was extra putty when the sink was installed and it cold be removed especially since one of them connects to the overflow. So I took out as much putty as I could with tweezers, but there are still some small chunks in there time to time swimming around

View attachment 95537

These four flange holes hold water and if I dip a Q-tip in those hole it smells like the rotten sulfur smell. Little chunks of putty I get out smell like it. Guessing every time I activate the sink water swishes in there and kicks up odor?

So, should these holes be filled with putty to prevent standing water from being in there?

Any other reason this flange would smell so bad? We do get an orangish build up that we clean every few months beyond regular sink cleaning.

Anything I can try? Thanks!

I would sop up the water in the overflow holes. Then clean the inside of the drain cylinder.
Block the overflow outlet holes with plastic electrical tape.
See if that stops the odor from stagnant water in the overflow.
If the overflow is ever used the water pressure willikely push outhelectical tape and drain.

 

[bingow]

I thought it was just our sink with this problem. Every 3 to 6 months, I have to treat our upstairs lav: close the stopper, pour a few ounces of Liquid Plumr down the overflow hole, seal the hole with tape, and leave overnight.

 

[Reach4]

While also possibly releasing chlorine gas, a chemical weapon.

Don't ever do this. While someone very experienced could carefully control the pH throughout the process to avoid releasing chlorine gas, the pH of vinegar alone is enough to liberate chlorine gas from bleach. The risk/reward ratio is way too high.

Cheers, Wayne

Thanks for the warning. That chorine production does not happen with the pH above 5.

But chlorine bleach is a lot more active at pH 5. So I figure to add the vinegar first, and let that mix. Then add the bleach.

My study of this was aimed at well sanitizing. I use a cheap pH meter to measure the whether to increase the vinegar. I am careful to not mix bleach and vinegar directly. While vinegar is a weak acid, in its 5% form, it can indeed cause chlorine generation. And generation in bathroom sink would be a lot more dangerous than down a well.

 

[Dvid]

You could pull the trap apart. Seal the tailpiece with a plastic sheet/bag held in place with a rubber band. Fill the bowl above the drain holes.

If you first drop the pH with vinegar, and then add chlorine bleach, you can make your solution in that blocked sink very effective.

While the septic can handle some chlorine bleach, you could drain the tail piece into a bucket.

I like the idea of blocking the flange holes and filling up some of the overflow reservoir with the p-trap removed and a bucket to catch the liquid instead of it going in the septic. If I do I'll heed @wwhitney advice to not combine vinegar and chlorine. I might do vinegar first. Then thoroughly rinse with water, then a bleach water mix, then thoroughly rinse. So more or less a two step, separate process.

I just hope I don't have to do this every 3 months!

Thanks guys.

 

[wwhitney]

The one time I have wanted to sanitize a sink drain (on a kitchen sink, not a lavatory sink, so this issue of the overflow cavity and the holes was not at play), I created a slip joint cap by gluing a spigot end trap adapter into a cap. Then I removed the slip joint trap and put the slip joint cap on the sink tailpiece, so that I could fill everything up with diluted bleach.

Cheers, Wayne

 

[Dvid]

I thought it was just our sink with this problem. Every 3 to 6 months, I have to treat our upstairs lav: close the stopper, pour a few ounces of Liquid Plumr down the overflow hole, seal the hole with tape, and leave overnight.

Interesting. I think this is basically what others are recommending but with vinegar and / or bleach. @wwhitney made and important point to NEVER combine vinegar and bleach together.

Glad to know I'm not the only one with this issue so I appreciate you making me feel less alone in this. I hate that smell!

 

[Dvid]

The one time I have wanted to sanitize a sink drain (on a kitchen sink, not a lavatory sink, so this issue of the overflow cavity and the holes was not at play), I created a slip joint cap by gluing a spigot end trap adapter into a cap. Then I removed the slip joint trap and put the slip joint cap on the sink tailpiece, so that I could fill everything up with diluted bleach.

Cheers, Wayne

Fancy.

I'll just remove the p-trap and put a 5 gallon bucket (or smaller bucket on a tote or something) right under the drain flange and tail piece to catch all the cleaner / water and splash.

What's causing all this? Who knows? Maybe the initial 2-3 years the putty was in the flange holes bacteria grew in the overflow reservoir that I've never fully gotten with the squeeze bottle with vinegar and brush.

It is odd in this house that the orange slime grows quickly on the popups. All the water tests are fine except manganese and that according to Google usually smells different / looks different like a black and smells like asphalt. Never seen or smelled that. Even the manganese though has been taken care of by the softener. It's high on pre-softener water tests and low on after softener tests. I do use res-care to try and keep the softener in shape.

So let me...

1. block the flange holes (probably with heavy duck tape)
2. remove p-trap and clean it and have bucket in place under the drain pipe so chemicals don't go into septic
3. fill up the overflow reservoir with vinegar and let sit
4. remove the duck tape from flange holes and rinse with water
5. duck tape flange holes again
6. fill up overflow reservoir with water to get any remaining vinegar to prevent interaction with bleach
7. remove duck tape from flange holes to drain
8. replace duck tape on flange holes
9. fill reservoir with bleach / water mix and let sit
10. remove duck tape from flange holes and squeeze bottle water through there to get initial bleach out
11. replace duck tape on flange holes
12. fill up overflow reservoir with water to get remaining bleach
13. remove duck tape from flange holes
14. replace p-trap and test for leaks
15. go on with my life.

Going to do this next week and will report back. I'm confident it will take care of initial smells. How long it will last who knows. I'll report back. THANK YOU ALL!

 

[Reach4]

If somebody did want to study a bit on pH with bleach, https://hyposource.com/blogs/storie...orous-acid-versus-bleach-whats-the-difference is pretty good.

Divd, what did you think of "For your [tailpiece] holes, you could file the bottom of the holes to let standing water clear."

 

[Dvid]

If somebody did want to study a bit on pH with bleach, https://hyposource.com/blogs/storie...orous-acid-versus-bleach-whats-the-difference is pretty good.

Divd, what did you think of "For your [tailpiece] holes, you could file the bottom of the holes to let standing water clear."

I had replied that might be beyond my homeowner DIY abilities. I'm not sure I'd have the tool for filing the metal. I could envision damaging the sinks if I filed too aggressively. The porcelain "channel" where the flange holes are is recessed below the metal so filing wouldn't eliminate all the standing water in the channel. I'm not sure what the metal is either. Filing it might cause it to rust, I dunno. I also think the standing water in the channel gets circulated every time I run the sink. So, I don't think the water in the flange is necessarily the stink problem because water in our rarely used toilets would stink and it doesn't.

Some of those chunks of plumbers putty that still appear really smell bad and appear to have growth on them. I'll start with sanitizing the overflow reservoir and see how that goes. Thanks again for all your great ideas!

 

[Reach4]

Metal is likely brass. Metal that rusts is attracted by a magnet, so there is an easy test.

The tool would be a file, and I am thinking that a "rat tail" file would be appropriate.

But some easy sanitizing may cure your problem.

 

[Dvid]

So far about two weeks and no new smells from the p-trap since cleaning with bleach water, rinsing then vinegar/ water.

Only time will tell if it was long term bacteria / mold in the overflow area that I killed off or if after 6-12 months the ptrap starts stinking again. I will say that when I sniffed the overflow hole for the reservoir I never smelled that bad smell, but when I undid the p-trap it was DEFINITELY that smell.

Everything is as clean as possible for now all the way to the pipe in the wall. It could have been caused by enough gunk in the ptrap but there wasn't much. It's almost as if each use of the sink let in enough gas from the p-trap that it made it's way up the tailpiece. Still not 100% sure.

Did notice one sink's tailpiece is rusting a bit so that material isn't good for filing.