Replaced air admittance valve

RickV · 05-07-2019, 06:15 AM

We started getting the rotten egg smell coming from under the bathroom sink after taking a shower so, I did some searching and it appeared that the problem was the air admittance valve was the problem. I replaced the valve and while not as bad the smell is still present after someone showers. I didn't put any Teflon or plumbers dope on the threads could this be the problem?

Witch Doctor · 05-07-2019, 06:38 AM

Quote:

Originally Posted by RickV

We started getting the rotten egg smell coming from under the bathroom sink after taking a shower so, I did some searching and it appeared that the problem was the air admittance valve was the problem. I replaced the valve and while not as bad the smell is still present after someone showers. I didn't put any Teflon or plumbers dope on the threads could this be the problem?

Could be but I doubt it, your probably smelling the soap scum in the tank on the side walls. Is your shower and sink on the same gray tank? Gray tanks can get nasty also. You get a oder eliminater and cleaner for the tank it's a tablet. Place it over the drain and add water. If mine still smells I just mix a black tank pack in some water and pour it down the drain. Another question are you smelling the rotten egg smell from the faucets, that's a different thing from high sulfer content in water like from a well system. Before I would do anything else I would clean the tank first.

TheWolfPaq82 · 05-07-2019, 06:57 AM

X2 from the Doctor. Few years back we had the bad smell coming from drains. Realized it was gray tank while at dump station before coming home from a trip. Got home and put in bottle of "Blue Stuff", filled the tank and let it set all week in driveway. Flushed the tank the following weekend and all the odor disappeared.

RickV · 05-07-2019, 07:02 AM

We put the stuff in the tanks but, the smell is coming from "under" the bathroom sink and only when taking a shower.

Witch Doctor · 05-07-2019, 08:07 AM

Quote:

Originally Posted by RickV

We put the stuff in the tanks but, the smell is coming from "under" the bathroom sink and only when taking a shower.

I would think that the sink and shower are connected, so the smell can come up the sink drain, is there a pee trap on the sink? Check that it holds water. I still think your tank needs better cleaning, put something in it. Fill the tank let it sit in it over 24 hrs, even better drive with it and slash the water around then dump it, see if it helps. There is no real magic here that I know of, good luck...can you bypass the admittance valve? See if that helps. An admittance valve admits air.

Witch Doctor · 05-07-2019, 08:10 AM

Also check your vent pipe if you have one connected to that tank. There is really nothing else you can do.

5picker · 05-07-2019, 08:17 AM

Do you have a black tank flush?

The anti-siphon/check valve for the flush is typically under the bathroom sink and has been known to cause this problem as well as leaking water issues.

Also... some showers ARE plumbed to the black tank!

Brewster McFrisk · 05-07-2019, 02:26 PM

We use pinesol or Dollar Store equal. Works for us and is way cheaper.

CedarCreekWoody · 05-07-2019, 04:42 PM

Are you running a vent fan while showering? If so be sure there is a vent or window open to allow make up air to enter. An exhaust can create enough suction to overpower an AAV and suck in Air from the grey tank. You could try a shower without running the exhaust fan as a test. For a further test, if necessary, cover the AAV with a plastic bag and tape it tightly. Finally be sure the grey tank vent line is open as the shower water going into the tank has to force out displaced air through some source.

salwolfe · 05-09-2019, 07:26 AM

Had the same problem during the first days of our rig and went thru some of the same steps that commenters are advising on, including replacement of the air admittance valve. I think the end result solution was "blowing" out the shower drain and then putting a $5 plastic drain cover (good ole Wally World) on it to keep hair, etc. from going down the shower drain. Clean the cover after every shower and voila, fast drain every time and no smells anywhere including the kitchen.

RickV · 05-13-2019, 05:55 PM

I appreciate all the replies and suggestions. I took a Wally World bag and put it over the air admittance valve and sealed it with a rubber band. Smell is gone now when showering. I guess the new air admittance valve was bad outta the box. I am sitting here wondering why there is the need for the air admittance valve in the first place and if I can just seal off the riser and if I would have problems.

Iwannacamp · 05-13-2019, 06:28 PM

I have a stupid question. Any chance you installed it backwards? Had to ask. The stuff is usually plastic and I cannot see how the threads would leak under vacuum of ounces of pressure.

We had a similar problem when reaching a destination. Peeeyewww smell in the RV. Not there when we left, but there upon arrival. We decided it was the grey tanks/tanks. I bought some grey deodorant(yellow liquid crap) and it helped a lot.

CedarCreekWoody · 05-13-2019, 06:32 PM

Be sure you are not running a powerful exhaust fan unless you provide a other way for make-up air to enter. Otherwise it can suck air through the AAV. You may experience slow sink draining at times with it blocked.

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