Do I have a Black Tank issue?

[hlh1]

Today was my first time to dump the black tank and all seemed to go well, but now I seem to have a lot of "urine" like smell around the toilet area.

I dumped the Black tank and used a "Valtera" (I think it is) to back fill the black tank and released the water 3 times until all was clear. I let the hose run about 2 minutes and then let it release to clean things out. The black tank is 37 gallons and wonder if I may have over filled it with the Valtera? I've looked under the TT and have no water dripping. I opened up the panel under the shower next to the toilet and see nothing wet in the area below. There was no water around the toilet anywhere. I used a bucket to dump about 10 gallons of water back into the black tank after dumping it and added some septic enzyme. I'm leaving about an inch of water over the toilet valve.

Maybe this is just normal? But I didn't have this smell before. Am I missing something? If I did "back flood" the black tank where should I look to find any issues?

thanks!!

[bsmith0404]

I doubt you have any problems. No way you overfilled 37 gallons in 2 minutes. Sometimes the sewer gas just gets into the tank/rV while dumping it. How long has it been? The only place to look is in the underbelly around the tank, sounds like you’ve already checked all of that. Open the roof vent and let it all air out a bit, my guess is it’ll go away.

[hlh1]

Originally Posted by bsmith0404

I doubt you have any problems. No way you overfilled 37 gallons in 2 minutes. Sometimes the sewer gas just gets into the tank/rV while dumping it. How long has it been? The only place to look is in the underbelly around the tank, sounds like you’ve already checked all of that. Open the roof vent and let it all air out a bit, my guess is it’ll go away.

I dumped it at noon today and I'm still smelling it 8 hours later. I've opened the roof vent in the bath room, like you suggested. Guess I'll just wait it hope it goes away.

[JRTJH]

If you have the roof vent open in the bathroom and the vent fan turned on to help clear the air, you may be sucking black tank odors from the vent stack which is usually somewhere fairly close to the bathroom roof vent. Even with the vent fan turned off, if the wind is blowing the right direction, the venturi effect can dump black tank odors into the cabin.

So, as "dumb as it sounds", close the bathroom roof vent and open a side window in the front of the trailer and another in the rear of the trailer and let the "natural airflow from the sides, not from the roof" air out the trailer.

What brand/model toilet do you have ??? Some model years of Dometic 300 toilets have a leaking bowl/base gasket that can cause a similar odor and more than a few Thetford toilets are known to have "lingering smells"....

So, if the ventilation from side windows doesn't help, after a couple days, if the problem persists, you might start looking at the toilet gasket as a possible cause.

[hlh1]

Hi John,

I have the ceiling vent open but the fan is not on, and yes the black tank vent is very close to the vent. I'll try what you've said and close the vent and open the TT windows to air things out. I do think I smell is more around the toilet. I have a Dometic but not sure the model and I'll check in the morning.

[wegone]

I am a plumber by trade....

You describe the classic symptoms of a failed seal under the toilet.
I wouldn't be surprised if the seal is crimped, or maybe even missing, as this is your first time using it, right?
You never smelled it until after you dumped the black tank for the first time?

My "best guess" is when you introduced a little more pressure to flush out the tank, it was enough to cause the "iffy" seal to open up, it doesn't take much, believe me.
I have had to track down a sewer fume in large homes on septic tanks, that can make even a ripe old plumber green, to a failed wax ring in one toilet.
It wasn't showing any water leak at the base, but fumes are so much smaller.

Good luck, where should I send my bill, I need to buy a gallon of gas

BTW, I see you have a 5.0 in a F-150, I'm guessing you have a tow package with a 6 speed tranny what rear end.... how does it handle your trailer?

[hlh1]

Originally Posted by Island Eddie

I am a plumber by trade....

You describe the classic symptoms of a failed seal under the toilet.
I wouldn't be surprised if the seal is crimped, or maybe even missing, as this is your first time using it, right?
You never smelled it until after you dumped the black tank for the first time?

My "best guess" is when you introduced a little more pressure to flush out the tank, it was enough to cause the "iffy" seal to open up, it doesn't take much, believe me.
I have had to track down a sewer fume in large homes on septic tanks, that can make even a ripe old plumber green, to a failed wax ring in one toilet.
It wasn't showing any water leak at the base, but fumes are so much smaller.

Good luck, where should I send my bill, I need to buy a gallon of gas

BTW, I see you have a 5.0 in a F-150, I'm guessing you have a tow package with a 6 speed tranny what rear end.... how does it handle your trailer?

Hi Eddie,

Thanks for the diagnosis. Now I just need to find some instructions and
parts to fix this.

My 2015 F150 has the heavy duty towing package and the 5.0 V8. The TT has a GVW of 7000 lbs and the F150 is doing fine with this, but I've towed it now only 3 times and not over any mountain passes. My friends have the turbo motors and they tow better, BUT at around 75k miles the turbos often need to be replaced for about $9000.

[Scttw]

Don't pee - standing up, when you're drunk

[dutchmensport]

Originally Posted by Scttw

Don't pee - standing up, when you're drunk

This may be tongue-n-cheek for sure, but it is really true though. No so much the "drunk" part, but peeing on the floor. OK guys, you know what I'm talking about. It only takes one "drop" on the floor and within a couple hours that single drop smells like the city sewer plant.

My suggestion for the OP, bleach water wash the entire area around the toilet, including the toilet itself, inside and out, toilet seat, everything. See if the odor goes away.

Good luck!

[hlh1]

Originally Posted by Scttw

Don't pee - standing up, when you're drunk

Good point, and I understand. I did think about this and wiped the whole area with bleach wipes just in case I missed... No improvement.

[Scttw]

hehe - well on a serious note, It's very strange that "Urine" over powers the traditional septic type fragrances ....... mind boggling actually.

Keep us up to date if you get it figured out. PS - one of my Fav State Caps if it's VA you live in!

[bsmith0404]

You’ve been given a lot of great ideas. One thing I’ve noticed is nobody seems to think it’s a black tank issue. If you’re still getting the smell after all this time, it’s probably time to pull the toilet and investigate the seal and clean around the base.

[hlh1]

Originally Posted by bsmith0404

You’ve been given a lot of great ideas. One thing I’ve noticed is nobody seems to think it’s a black tank issue. If you’re still getting the smell after all this time, it’s probably time to pull the toilet and investigate the seal and clean around the base.

Yes, I'm looking at replacing the toilet seal.

[JRTJH]

There are two "toilet seals" on the Dometic toilets. One is the seal that fits on the base/floor adapter and seals the water/waste going down the toilet and prevents black tank gasses from "seeping up into the bathroom" around the base/floor adapter...

The other seal, the one that Dometic had issues with, is between the base and the toilet bowl. IT IS NOT REPLACEABLE, although there are a few "stubborn owners" who have pulled the toilet apart, cleaned up the space, resealed with a "homemade gasket and lots of gobbed silicone" and achieved success... I don't have any reliable statistics, but I'd guess for every "successful owner" there are likely 10 that get frustrated and give up, can't get the gasket to work, break the plastic base or strip out the threads trying to get the bowl tight enough so it won't leak.... So, proceed at your own peril....

Dometic did have a program to send owners with the bowl/base leak issue a replacement toilet. I don't remember the dates they approve or disapprove, but if the base/floor gasket doesn't fix the problem, before you go spending $200 for a new toilet, give Dometic a call and see if your toilet is included in their replacement program.

Oh yes, and the base/floor seal is not a wax seal, it's a specialized foam seal, so don't attempt an "aftermarket make-do from the plumbing department at the local hardware store"....

[skids]

I have not had an issue with my Dometic 300, but I read on another site that the change of the seal to correct the internal stench started with serial numbers starting with “4”. I don’t know how true that is but I thought it was worth mentioning.

[hlh1]

The PO kept all the TT documents and I see I have the Dometic 300 and the exploded view shows the Floor Flange Seal that probably needs replacing. I'll order one shortly.

[IggyD]

I leave about 2" of water in the toilet when the trailer isn't moving to keep gases out of the camper.

[hlh1]

I think I'm going to do this when I install the new floor seal:

https://www.youtube.com/watch?v=VYqvhgdU4Po

[sourdough]

This is sort of farfetched, and not with a Dometic 300...but it happened to me.

I haven't pulled up a pic of the inside of the Dometic 300 pedestal. When I did that with a Thetford I found that they made several "pockets" around the inside of the base. The toilet developed a leak inside that we could not see. When the smell finally began to get bad I searched and searched for the source without luck but I knew it was in/under/around the toilet. I didn't like the Thetford anyway so since I was going to pull it I got a Dometic 310. Pulled the Thetford, placed the Dometic and carried the Thetford to the dumpster. BAD move. As I held it and picked the base up to put over the edge of the dumpster the entire contents (aged) of those pockets poured right out, down the sides of the toilet and promptly soaked me - it didn't smell like lilacs I promise.

Long story to mention a problem that "might" be and a warning that if that is what it is, be CAREFUL when you dispose of it.

Edit: You said it smelled like urine and you can't get rid of it. I highly doubt that is the black tank as it doesn't smell just like urine. I would be checking that toilet for bowl leaks, residue where it liquid (urine) has run under the base of the toilet etc. I suspect if you pull it you will find the problem....just be careful if you carry it to the dumpster....

[hlh1]

Danny, that's exactly what that video is showing that I posted. Internal gasket leaks that settling in areas and you get the smell...