Holding tank odor

[Georgetownjim]

Am newbie to forums so thanks in advance for any help. I have read all posts that come up under "odor" search. No help so far. Have any of you seen or heard of this problem? When I look into the black tank through the open flush valve the inlet pipe (that extends down from the floor flange) seems to extend too far into the tank. When the tank is about half full the effluent covers the end of the inlet pipe. I bent a coat hanger wire into a tight "J" shape with about 4 inches curved back up and probed the inlet. I was able to confirm that the inlet pipe extends at least 4 inches into the tank or about half the depth of the tank. When the liquid gets up to that depth the odor is impossible to control. Has anyone seen a black tank inlet made like this? I suspect sloppy assembly since their was plenty of it in other areas of this 2008 Georgetown 357 quad slide class A. Any thoughts on a solution? Thanks...gtj

[Jim_Norman]

We had an issue with odor. Found out that if the vent in the head was open it would somehow suck in fumes off the roof and the rig would stink. learned to close the roof vent when driving and no more troubles. Of course our issue only occurred while driving.

[kg1d_dx]

I had a hookup for a washer and the pipe for the washer drain was not capped and since their was no washer the trap had no water in it to block the Oder. Put a cap on the end of the pipe and that solved the problem.

[Georgetownjim]

Thanks crasser. I did drill 20 or so holes about 3 inches up the pipe. That helped until I found the unsealed vent pipe at the roof line. I still need to dremmel the inlet as you suggested.
By the way for others who may be dealing with a similar situation, vent cap products that claim to "draw odors out" are a joke. Where would it draw from? I figured that out when I was thinking of installing a fan at the top of the vent pipe. For "air" to come out it has to go in somewhere. These tanks don't vent in the sense of a continuous flow. Air comes out when liquid goes into the tank and air goes in when u drain the tank. Other than thermal expansion and contraction and release of methane from the sewage there's no other "venting" going On!
And yes I did install an "aero" cap but only because I had it already.
Thanks again "y-all

[crasster]

Also if you are really brave and want to remove the toilet you may be able to get a Dremmel cutting tool in there and take back some of the pipe. In the mean time it may really help to use a lot of extra water when you flush.

The next most important part of an RV besides the Engine and Transmission is the black tank! I wish mfg's would get those right!

[Heisenberg]

On long trips keep your ptraps filled with water.

[DSDP_Don]

You still need to pull your toilet and shorten the pipe. Once the tank gets to a certain level, waste will stay in the drain pipe from the toilet and smell every time you flush. You can leave it alone, but your losing a lot of black tank volume if you have to dump at half a tank.

[tropical36]

Georgetownjim wrote:
Am newbie to forums so thanks in advance for any help. I have read all posts that come up under "odor" search. No help so far. Have any of you seen or heard of this problem? When I look into the black tank through the open flush valve the inlet pipe (that extends down from the floor flange) seems to extend too far into the tank. When the tank is about half full the effluent covers the end of the inlet pipe. I bent a coat hanger wire into a tight "J" shape with about 4 inches curved back up and probed the inlet. I was able to confirm that the inlet pipe extends at least 4 inches into the tank or about half the depth of the tank. When the liquid gets up to that depth the odor is impossible to control. Has anyone seen a black tank inlet made like this? I suspect sloppy assembly since their was plenty of it in other areas of this 2008 Georgetown 357 quad slide class A. Any thoughts on a solution? Thanks...gtj

That being the case, can you just not take it all apart and fix it like it should be?
If what you're saying is true, then it can't hardly vent, no matter where the vent pipe might be.
All else fails, you'll just have to dump more often and even though waiting for a 3/4 tank is best. If you have cleaning nozzles installed in the tank, so much the better.

[Georgetownjim]

Sorry about the delay in my followup response. I bought a " aero" roof vent cover. Old one was cracking. On removing the old one I discovered the source of my odd odor problem. The 1 1/2 " pipe was simply sticking through a 2" hole in the roof. No caulking or sealant of any kind aND it wasn't sealed to the vent to cover. So under certain conditions ( nearly full tank) the sewer gas rising up the vent pipe would simply diffuse into the ceiling and walls and out any non-airtight area into the bathroom. After sealing there I haven't had a serious odor problem. I hope this helps anyone fighting a similar problem.

[Rick_Jay]

GeorgetownJim,

I, too, fail to see how the toilet inlet pipe extending too far into the black tank would create an odor problem anywhere. I could see it reducing the time between black tank dumps.

If you're getting an odor from "there", which I'm assuming is a point difficult to locate, I would guess that your vent pipe to the roof is either cracked or loose, either at the tank connection or somewhere inside the wall. From the vent outlet on the roof, try to figure out which wall has the vent pipe in it and see if you can locate the odor to that wall. Perhaps noticing that it is stronger inside a cabinet or drawer against the wall, or where that wall meets an abutting wall.

Good Luck and keep us posted on your results,

~Rick

[TNGW1500SE]

Georgetownjim wrote:
Thanks folks. Have tried all the great suggestions. Inlet pipe is definitely too far into tank. I suspect a poor glue connection of the riser to the roof vent. The odor does not come from near the commode, sink or drains. It is just
"there" The logical solution to me is to
shorten the inlet pipe.or drill it full of vent holes with my 90 degree drill adapter & short bits! What do you think?

I'm still not understanding where the smell is getting into the RV. When the toilet is shut it's sealed. No fumes should get back into the RV short pipe or not. Everything should vent out the roof.

If I were going to shorten the pipe, I'd hook a wet/dry vac to the dump valve and hose it to the neighbors yard while cutting it. I'd worry about plastic falling in the tank as well. When done I'd sell all tools used on Craigslist.

[Georgetownjim]

Thanks folks. Have tried all the great suggestions. Inlet pipe is definitely too far into tank. I suspect a poor glue connection of the riser to the roof vent. The odor does not come from near the commode, sink or drains. It is just
"there" The logical solution to me is to
shorten the inlet pipe.or drill it full of vent holes with my 90 degree drill adapter & short bits! What do you think?

[garymunson]

I had the EXACT same problem with my previous Fleetwood Flair AND our new Winnebago Vista. Don't understand why the 'drop pipe' has to go so far down into the tank. What I have gotten into the habit of is, after using the toilet for 'number 2', I'll refill the bowl with water to the top (holding the pedal partially down) and then flush the bowlfull of water. This seems to disperse the solid waste and prevent the buildup at the drop pipe. Also, the extra water seems to help when you dump the black tank. If you let it build up too much, it can get solid enough down there to prevent any further waste from entering the tank and you will have what looks like a stopped-up toilet. Nasty. Before it gets that bad, you'll probably notice the flush goes down with air bubbling back along with the familiar stink. Since we adopted the 2nd full bowl water flush procedure, we have not had the problem. Still do not understand the 'long pipe'...

[TNGW1500SE]

Mvpmich wrote:

TNGW1500SE wrote:
I don't see how the pipe would cause an odor even if it is "to far down" in the tank. Does the odor come from the toilet of could it be from the sink? Some RV's a plumbed so the bath sink goes into the black tank. Check for a vent under the bath sink

If the vent pipe is too far down in the tank it could be below the fluid line and therefore prevents air from escaping. The problem is probably twofold, 1) the tank needs to be flushed and cleaned and possibly sanitized to rid any long standing or built up materials and 2) better exhausting from the vent stack.

I had similar problems after I dumping and thought the tank was empty and clean only to find residual waste as well as back drafting while driving. I installed a Camco Cyclone swivel cover on the vent stack that allows the wind to suck out the odor either while driving or stationery. There are other types including the DIY "t" mentioned that will give you the same results.

He's talking about the pipe from the toilet to the tank being to far down.

Shouldn't the toilet seal in all the odor? It does on mine. If I wanted to smell the black tank, I'd have to go on the roof.

PS: I have no plans to do so 😉

[D_E_Bishop]

I have a feeling that your waste pipe from the toilet may be too long and the only thing that should do is reduce your time between dumps. You may have to measure your black tank height and the compare that figure with the distance from the bottom of the waste to the bottom of the tank.

I had a similar problem with my newly purchased Winnie and I did a really great flush, cleaned and lubed the flappers in the AAVs, replaced the seal in the toilet(the bowl wouldn't hold water)and no more odor. I have a Tornado flush system. I also have a hose flush fitting on the elbow from the knife valve.

No odor.

Good luck.