More in the ongoing toilet smell saga...

[am1958]

In another thread here I documented the beginning of our stinky woes. I had the trailer here for a few days and thoroughly cleaned the black tank and let it sit to see if it began to smell again. It didn't seem to but then again it was pretty spiffy clean and full of Dawn and water with some added Borax.

Went out Sunday and within three or four times of peeing in it, (we tend to use the State Park facilities for pooping and just use the toilet for pee), the bathroom started to smell like the stairwell of a multi-storey car park. We turned on the fan, made sure we used plenty of water but the smell would not go. The seal is good and holds water indefinitely so my next guess was the vent pipe. Up on the roof I went and removed the cap and wasn't surprised to find I couldn't smell the nasty smell... Bingo, thinks I, problem solved. My makeshift snake was 2 three quarter ounce fishing weights clipped to the end of a line and dropped down the vent pipe. Strangely they went straight down, unimpeded, until I clearly heard them hit the bottom of the black tank. Conformation that it was the black tank was the few little bits of paper clinging to the line when I retrieved the weights.

So, I have a good seal at the ball and a clear vent stack so my best guess is the seal under the commode itself isn't "sealed". It clearly allows the waste to go down without leaking out but I'm guessing that it isn't "sealed" and is letting out the smell before it can go up the stack. This being my first trailer I'm inexperienced in the amount of wobble a toilet has but mine does seem to move a bit when my old carcass hits it.

So, before I rip the toilet out to try to fix or replace the seal I turn to the collective knowledge of RV.Net and ask, is there something less strenuous I should try first?

[winger999]

TyroneandGladys wrote:
Very good chance what your smelling is not black at all but grey tank. Grey tanks can have a very foul smell also.
The water can evaporate out of the p traps allowing grey tank smell to come into the RV. Run water in all the drains and you might find no more odor. I have seen this work numerous times. The leading culprit is the shower drain because people use it for storage and never run water down the drain.
Please post if this takes care of it or not.

We had the identical problem two weeks ago, and this was the exact problem. We use our shower for storage and the grey tank smell was coming from the shower drain. Ran water in the shower, smell gone.

[PUCampin]

TyroneandGladys wrote:
Very good chance what your smelling is not black at all but grey tank. Grey tanks can have a very foul smell also.
The water can evaporate out of the p traps allowing grey tank smell to come into the RV. Run water in all the drains and you might find no more odor. I have seen this work numerous times. The leading culprit is the shower drain because people use it for storage and never run water down the drain.
Please post if this takes care of it or not.

Definite possibility. I have to refill all my traps after almost any drive, or after sitting a couple weeks. Bumps cause it to slosh out of the traps, or evaporation if sitting.

[TyroneandGladys]

Very good chance what your smelling is not black at all but grey tank. Grey tanks can have a very foul smell also.
The water can evaporate out of the p traps allowing grey tank smell to come into the RV. Run water in all the drains and you might find no more odor. I have seen this work numerous times. The leading culprit is the shower drain because people use it for storage and never run water down the drain.
Please post if this takes care of it or not.

[Lynnmor]

Your vent pipe test was not complete. Go back on the roof with a garden hose and see if it takes a full stream of water and not fill the vent pipe. The skilled craftsmen that assemble these things have been known to allow the vent pipe to drop to the bottom of the tank rendering it useless.

[DC_MC]

Put a new vent cover on top. Get the kind that twirl in the wind.

[Jack_Spratt]

, "before I rip the toilet out to try to fix or replace the seal"
It really isn't much of a project.
Pick up new seal for $5, disconnect the water, undo two nuts (probably 9/16)
Remove the old seal, clean and replace.
Total time ....1/2 hour
There must be a you tube video to guide you through the project.

[Ski_Pro_3]

Try using smoke to discover the odor leak. Start with a clean tank again. Open the dump lever and place a bug bomb in there and close it up.

Most bug bombs are foggers, not really smoke but a mist. Here's a brand that makes smoke. You put the cartridge in water, a chemical reaction heats it up and it's smokin' away enough to set off the smoke detector in my house.

[Old-Biscuit]

Are you SURE it is black tank odor and NOT grey tank odor??

Inside bathroom cabinet on sink drain line should be an 'Air Admittance Valve' that is hand screwed into a stub pipe just after 'P' Trap.

It allows air in when draining grey tank so negative pressure doesn't suck 'P' Trap dry

If it fails to close grey tank odors can come inside RV.....grey tank can stink as much as black tank

Just something else to check ........

Toilet floor flange is a rubber/foam gasket
Toilet should be tight (no wobble) to floor---just like at home

[Justaguy]

Yep, that toilet should be solid against that floor. Really, it's not that big of a deal to replace that ring if you should decide to pull it out. Just make sure you put it on right side up. There is a right and wrong way to fit that ring. Youtube has some good video....

[Pangaea_Ron]

I only use the fan when the toilet is not open and actively flushing. It tends to pull odors from the black tank into the toilet room when the valve is open.

I always leave the roof vent open in the toilet room (no fan), do my business, flush, and when done and the valve is closed, I then turn on the fantastic fan for a couple of minutes to clear any odors while I'm washing my hands.

[PUCampin]

What kind of toilet do you have? My original was a Aqua Magic V with a flush handle. The underside of the bowl of the Aqua Magic V is essentially a large chamber that funnels down to the pipe going into the black tank. The flush handle shaft penetrates into the large chamber, which is open to the black tank, to activate the blade. On mine the seal went bad and allowed black tank odors so seep out where the handle attached. It took me a LONG time to determine this is where it was coming from. There is no replacement seal though I have since heard it is a grease seal. The aqua magic V is essentially a disposable item. I bought a Style II as a replacement. I also installed one of those vent caps with a small computer type fan. It creates a very slight negative pressure in the tank and encourages air to seep into the tank through any leaks rather than odors seeping out

[diazr2]

I would think if it is leaking at the base it should be noticeable. Fill the tank all the way to the top!! To where the water is all the way up in the bowl. If it has a leak at the base it will show then for sure. If not try some Happy camper.

[DownTheAvenue]

The toilet should be firm against the floor and have no wobble. That may be the problem.