How to correct Mildew smell coming up from inside the bathroom sink drain?

We have had the walls examed and there is no leak in the wall or underneath the sink. There is a strong mildew smell coming from inside the drain. We have tried drain-o, tilex and even bleach but the smell keeps coming back within hours. Any adivce? Do you think having the sink snaked would help?

I get this too, even though my trap is fine. I think it comes from buildup inside the overflow,. not from the drain. Try an enzymatic product or bleach in the overflow before you spend all that $$$..

Using the sink stopper, pour one cup of bleach into the sink. Slowly (to prevent splashing) add water and let it go through the overflow hole(s). Let the water run until you no longer smell the bleach. This will disinfect the inside walls of the sink. As far as snaking the drain, it won't help. The trap retains water to avoid sewer gas from entering the house. If your trap is not bad, then the smell is coming from above it.

I have good luck with this....try putting a little baking soda down and around the drain, then close the drain so it is only slightly open. Then add a small amount of vinegar. This creates a bubbling effect. Cover the drain (I use a small bowl) and let sit overnight. Good luck!

Try snaking first. If that doesn't help, the trap may be deteriorated. Not too expensive to fix. The snaking will probably cost around $100. A reasonable plumber will charge you less than $200 to replace the trap (unless you live in a VERY old house...then it could be a bit more)

Worst case scenario is that your sewer is clogged/bad. Are you experiencing slow drains all over the house? You may need your main sewer line cleaned out.

Hey There! I had some major plumbing issues this week and found a snake myself for about $12 Cdn (at Canadian tire if you live in Canada, if not then any hardware store will carry them. (Note that they tend to have the expensive snakes in an easy-to-view line of sight but ask for the cheaper ones!!!). What I did was took off the p-trap which is the loop under the sink. You might need to get a wrench to get it off, particularly if it's old!). See if there are any clogs in there - but it doesn't sound like that is the case! Since you'll have the p-trap off, you can shove the snake into the pipe leading into the wall. Spin the snake so that you are actually drilling into the clog (if you actually hit one) other wise you'll just be pushing it along and clogging it further down.

Instead of putting the same p-trap back on, I would go to the store and get one with a valve on it so that you can clean it easily (without ever having to take it off again - and that way, you get the clog before it moves down the line.

Just to let you know, we had that smell coming from the bathroom pipes too, and it started draining slowly a few months ago and I tried the chemicals and such, to no avail...(hence getting the snake). We got what we thought was the clog, with the snake, but it turns out it was HUGE (it's an old house that we bought recently so the clog was larger than expected)... Anyway, turns out the clog was making the water sit in the pipes and it corroded the old metal pipes. It was also the clog that we were smelling! When we shoved the snake through, it just broke it through and we had water everywhere in our basement (after using the sink a few times, not knowing what was going on)... so if you have an old house with steel/ cast iron pipes - check the ceiling under the bathroom when you're done! (Happy to say though, there is no more mildew smell ;-). We fixed the pipes ourselves and it's all good as new! The folks at Home Depot will help you out tonnes if you want to try fixing it yourself!

Cheers!

This is probably from the overflow of the sink, as mentioned above - it's a difficult area to clean.

If you stopper the sink tightly with a rag (the stopper won't work because the overflow drains below it) you can fill the sink with water & bleach to above the overflow. You might also try to put the water/bleach into the overflow with a turkey baster.

Use caution, in any event.

This really sounds like a leaking trap to me, the elbow part, under the sink drain. The reason the trap is there is to hold water in the U shape, to stop gases from coming in through the pipes. It works like a seal. If the trap is leaking enough, it will leak out to a level low enough for gases to pass through the elbow and up the drain. Run water in the drain. Look for signs of water leaks. tap the elbow and listen to the sound. Should sound full. Later when you detect the odor, tap elbow again. if it sounds empty, then water is leaking out somewhere.

it could be the overflow but my guess is that if you were to take the trap off underneath the sink and also take out the metal/ceramic grid from the sink i.e. the bit the plug goes into you will find loads of gunk in there. i find lots of them even in very clean conscious homes, there are places that cant be got to unless you take things apart. unscrew the centre and do what you need to to remove it, clean or replace the waste, as it is called, and refit using sanitary silicone on the edge