Bad Smell from Under Bathroom Sink

[Dental Floss Tycoon]

Hello all, I have a 2004 3685FL and there is a bad odor, not sewer, coming from under the bathroom sink inside the cabinet. I checked the drain fittings and all are tight when I noticed a pipe with what seems to be a vent on the end connected to the sink drain after the trap inside the cabinet. Is this some sort of vacuum breaker? Grey tank empties no problem, sink and shower drains okay.

Any ideas?

Thanks in advance,

George

[rames14]

George -

I would bet you have a Washer/Dryer prep that you don't use. If so, take a bucket and open the hot and cold water faucets into the bucket. Don't gag, as it will probably be much worse than the smell you are already getting. Once flushed, your odor problem should be gone. Hope this helps, it did for us.

[OntMont]

Take a look at the "New Montana Owner with a Problem" thread. It seems be a similar situation.

[Dental Floss Tycoon]

Thanks for the assist.

We have the W/D hookups but don't have a W/D and have noticed a smell in the closet where the W?D would be installed. When draining the black tank, some of the gunk would be forced up the W/D drain pipe which would cause the smell. I cut the W/D drain pipe, flushed it out with a strong stream of water until it drained clear and capped both ends. No more smell in the closet. This odor is coming from the under the bathroom sink from what looks like a standpipe with holes at the top.

OntMont, do you have a link to that thread? I can't seem to find it.

[H. John Kohl]

That stand pipe with holes in it sounds like the check valve for the black tank flush. It may be defective.

[Dental Floss Tycoon]

It can't be for the black tank because it's tied into the bathroom sink's drain right after the trap. It does smell bad but not that bad

[OntMont]

This is the thread I meant: http://www.montanaowners.com/forums/...ad.php?t=35641

The black pipe with a vent that you referred to, is a vent, and could be the cause of your problem if it is not working right. You should be able to unscrew it from the pipe. If you need a new one, they are usually stocked at any hardware store.

[FLSTS03]

George, have you tried to take the ptrap from under the lav. and clean it? If you were getting gook backing up in the W/D line, it would be possible for that same gook to end up in the Lav trap too. I know you said he Lav drains fine but there still could be sewage in the trap with odor escaping through the house side..Just a thought. If you have an lp leak detector(hand held) you might check the area you memtioned eailier as some of those devices can pick up methane as well.

Steve

[Dental Floss Tycoon]

quote:Originally posted by OntMont

This is the thread I meant: http://www.montanaowners.com/forums/...ad.php?t=35641

The black pipe with a vent that you referred to, is a vent, and could be the cause of your problem if it is not working right. You should be able to unscrew it from the pipe. If you need a new one, they are usually stocked at any hardware store.

OntMont, I think you nailed it. I will be checking this out over the weekend.

Thanks to all for your help.

[KTManiac]

quote:Originally posted by Dental Floss Tycoon

It can't be for the black tank because it's tied into the bathroom sink's drain right after the trap. It does smell bad but not that bad

Perhaps you have a funky thing going on in your grey tank though. There are grey tank "sweeteners" available anywhere you find RV supplies.

But, most likely, it is the W/D supply lines or washer drain pipe.

[FLSTS03]

I have never checked an air admittance valve for a W/D vent. I assumed it vented to the outside. I will replace mine with a Oatey valve as the black type is usally cheap and typical not to code in a stick house. See link below as these are the types generally accepted. Be sure to click on the how to use link at bottom of page. Steve

http://www.oatey.com/Plumber/Shared/...lve+6+DFU.html