Sewage Smell

[mdbaggs]

I am a bit frusterated that I can't seem to figure out our sewage smell problem. It has mostly been noticed by my family and myself when we've been camping and hooked up to the sewage hookup. Whenever we are camped in this situation I leave the valves closed for the grey and black tanks. I do this to not leave sewage in the line and to use the grey tank holdings to flush out the line after dumping the black tank. I dump the tanks every day or every other day.
The sewage smell seems to occur independent of flushing the toilet. For instance we went to the beach for 4-5 hrs the other day and came back and the sewage smell hit us as we entered the front door. While we were gone the AC's were running as were the fantastik fans (blowing out), but obviously the toilet hadn't been flushed in hrs. The smell seemed absolutely the strongest immediately at the wall that the black tank vent passes through.
I've checked the rubber seal on the black tank where the vent pipe takes off and it is fine with the vent pipe firmly seated within. The seal mechanism for the grey tank under the bathroom seat is working fine. The smell is not noticable when we are traveling/driving the RV even with a partially full black tank including when we are flushing the toilet.
My DW insists that is something to do with being hooked up to the sewage, but I keep telling her that shouldn't/doesn't make sense as the valves are always closed. However, I am leaning towards agreeing with her, but can't figure out how it could happen?????
Anybody else out there experience similar issues.
I've been considering dismanteling the wall that the black vent passes through to see if it is intact or getting a plumber to scope the vent to check for its intactness.
All thoughts are appreciated. Thanks

[GreatWhite]

Try leaving the AC off.. and turn the Fantastic Fans to blow IN.. if there is any NEGATIVE pressure in the cabin of the RV.. it can draw odors thru the toilet.

As a downside to that, if the fans are close to a fantastic fan.. the odors going up the tank vents can be drawn into the RV..

Do you use a tank deodorizer? I never do.. and don't have a problem.. except on really hot days. Otherwise, I never do have a problem. Another thing, I would NOT dump every day.. you really should have some buildup of fluids with solids in the black tank before you consider dumping.. Use LOTs of sater in you r flushes.. the bacteria in the tanks need oxygen.. you don't want the tank to go anaerobic.. Lots of water and wait till the tank is about 3/4 full before dumping. Dump black tank first.. then the grey tank to help flush the hose.

Some people put something like Pine-Sol in their tanks.. not much. I don't cuz I can't stand the smell of it.

It IS POSSIBLE that the thru the roof vent may have broken loose from the black tank.. I had that happen once.. but, it's pretty unlikely.

Forgot to mention, the bad smell CAN be coming from the grey tank as well. Surprising what breeds on that one too.

[deandec]

Do you have a washer/dryer on the rig? If it has not been run, the trap dries out and produces the waste tank smell. We have to run it on a short cycle occasionally to add water to the trap.

[GG1]

Do not dump the black tank every day. Dump it only when its full. You probably have a build up of solids and no liquid in your black tank when you flush use a lot of water. If the coach is closed up with the exhaust fans on every bad odor in the coach is wafting through it to the fan opening. You also may have bad toilet seal at your flush ball if thats the case the fan is sucking the odors from the black tank right in the coach. There are also a few other reasons for the odor but these are the most obvious.

[Fred Cooper]

check or replace the vacuum break valve on the bath sink and kitchen sink. These can fail and produce bad odors.

A propane leak can also smell similar to sewer gas

Fred

[bdpreece]

Any chance you have a Sani Con sewer system? We fought horrible smell problems until I figured out that the 3 inch hose to the pump is made of a porous material that will allow odors to pass through it. I replace the hose with a non porous type and no more smells.

["007"]

May just have to replace one of these under your sink.
Can be found at Home Depot or Lowes or hardware store.

[mdbaggs]

I have already checked the air admittance valve and it does't seem defective. I removed it and sucked air through it, but couldn't blow air out of it. I put it back in place, but none the less, the dealer is sending me a new one to try anyway.
I don't think it is a bad toilet seal on the floor end or on the ball valve mechanism as it wouldn't only occur when we are hooked up to sewage drainage, but also when the black tank is full and driving down the road with the AC and fantastik vents on, which it doesn't.
I've considered the negative pressure situation created by the fantastik vents, but smell wasnt alleviated by turning these off. Mine are the cheapos and only blow out without a reverse mode.
We have been using the washer and dryer regularly and I dont think the traps from there are the problem. The smell is not remotely near the washer trap.
Brian (bdpreece), yes we do have a Sanicon sewer system, but I am not sure what 3 inch hose to the pump you are referring to. On our black tank there is one 5-6 drain in from the toilet. A 3 in vent line coming out the top in the middle of the blank tank (rubber gasket intact) and a 3rd one inch line coming off the front of the tank that is about one inch diameter, clear (no obvious material or fluid in it) coming off the upper portion (6-8 inches) from the top, it then goes out and bifurcates, one line going across to the opposite side of the rig and the other going up to beneath the shower. I have no idea what it is for, but am curious. Please elaborate on the 3 inch hose you are referring to.
Anyway, any further thoughts are much appreciated. Thanks

[bdpreece]

Quote:

Originally Posted by mdbaggs SNIP I have already checked thewasher trap. Brian (bdpreece), yes we do have a Sanicon sewer system, but I am not sure what 3 inch hose to the pump you are referring to. On our black tank there is one 5-6 drain in from the toilet. A 3 in vent line coming out the top in the middle of the blank tank (rubber gasket intact) and a 3rd one inch line coming off the front of the tank that is about one inch diameter, clear (no obvious material or fluid in it) coming off the upper portion (6-8 inches) from the top, it then goes out and bifurcates, one line going across to the opposite side of the rig and the other going up to beneath the shower. I have no idea what it is for, but am curious. Please elaborate on the 3 inch hose you are referring to. Anyway, any further thoughts are much appreciated. Thanks

Responded to your private message. If I have the answer please post for others to use the fix.

[Ed-Sommers]

I'm a full time type person and have on two occasions had this problem. Both times I have found that my actions caused the problem.

Like many people, when dumping, black goes first, them back flush the black tank with the grey water, the dump the grey.

My problem was that the cleaning/clothes washing ingredients (bleach) was interfering with the natural balance of the black tank.

Once I cleaned with non-chemical water, and stopped back-flushing, all is well.

If you can smell the bleach in your fresh water fill up, find another source for that also.

This probably has no bearing on weekend use where total emptying of tanks is the norm. My black tank has not been flushed out (cleaned) in 6 years and no foul smell exists and I use only WATER, no additives.

Ed

[Pogo]

if you have tried all of these great suggestions and you still have the smell, I suggest you pour a large glass of water down the shower drain, if you have not been using it.
The P trap may have dried up, allowing the gray tank odors to come up into the coach.

[Gerall]

Quote:

Originally Posted by deandec Do you have a washer/dryer on the rig? If it has not been run, the trap dries out and produces the waste tank smell. We have to run it on a short cycle occasionally to add water to the trap.

Ditto on the w/d combo. Had me puzzled as well. Filled every trap, but didn't even think about the w/d.