Bathroom smell after emptying tanks

[Jason.rhodes86]

On wait for about 20 minutes but once I finally got thru it was smooth. Replacement on the way should be here in a week. I’m going to try to take the old one apart and use some silicone around the inner seal. I’ve found a few videos where people have done this and it seems to work. Then worst case I jist replace it with new one and hope that one holds.

[Todd Burton]

Originally Posted by jsb5717

^^^Ditto this. Whenever I've had that stinky scenario I've used a 5 gallon bucket to pour 8-10 gallons of water into the toilet. Then I drop in a couple of the TST packets. Then just use the toilet as usual until the next time to dump.

It's possible that you're dumping it too often, that is if you're in one spot for more than a couple days. IMHO, the real solution to getting the tank to empty well is A LOT of water. You might be dumping your black tank without enough to do the job well. Even after just a weekend of camping make sure there is plenty of water before dumping.

Personally, I don't use the rinse connection. If there's enough water in the tank before dumping you'll never need it.

[emoji106]

[slow]

Originally Posted by Jason.rhodes86

On wait for about 20 minutes but once I finally got thru it was smooth. Replacement on the way should be here in a week. I’m going to try to take the old one apart and use some silicone around the inner seal. I’ve found a few videos where people have done this and it seems to work. Then worst case I jist replace it with new one and hope that one holds.

That is good news.
Hopefully that is the end of the issue.

[Dan Lockwood]

Didn't see any mention of the air vent check valve that's probably under the sink.

We had a similar issue in the living area/kitchen. We have two sets of tanks as we have a half bath in the garage.

The vent check valve under the kitchen sink had a bunch of little nats in the cap and some were in the little flapper rubber valve. I think they call these sewer nats.

And as said before, the grey tank can stink just as bad as the black tank.

When you drain the grey tank, it sucks air in the valve to let the water out in the hose.

We replaced the valve worth one from Home Depot and it worked just fine.

Just thinking, the valve in my upstairs bathroom is only accessible by removing basement panels. Hope yours is easier to get to. 👍

If the other fix doesn't work, take a look at the valve.

Good luck with your issue.

Dan

[DroughtBuster]

We camped with full hookups last time so I took the opportunity to really clean out my black tank. I have a clear connection for my dump hose so I can see what is coming out of the tank when I flush. I had to fill and the dump the tank four-five times before large "deposits" and toilet paper stopped flowing out with the water. I was filling the tank at least 2/3 full each time before I flushed. I was amazed at how many times it took to really get it clean. I plan to do this once a summer from now on and if possible at the end of our last trip of the year.

[BAPotter]

Originally Posted by Jason.rhodes86

On week vacation. Emptied tanks Tuesday and then yesterday, Thursday. After doing it yesterday the bathroom has smelled pretty bad, like a porta potty. The seal on the flapper is fine because it’s holding water in between uses. Could just need another dump with a good flush out or two? Any ideas?

Years ago I came across this interesting video of tank flush tests. Since then, I've used only the spray method for as long as I can get away with (sometimes 15 min or more, then if storing the trailer a full dose of TST liquid, for my size tank, mixed in 3-4 gallons of water and dumped down the toilet.

https://www.youtube.com/watch?v=dfTd0Slt_cU&t=229s

[travelin texans]

Originally Posted by Jason.rhodes86

On wait for about 20 minutes but once I finally got thru it was smooth. Replacement on the way should be here in a week. I’m going to try to take the old one apart and use some silicone around the inner seal. I’ve found a few videos where people have done this and it seems to work. Then worst case I jist replace it with new one and hope that one holds.

I'd recommend using a tub n tile caulk rather than silicone, it's removable, silicone is a PITA.
There are specific sealants for most jobs in/on a rv, in my opinion silicone is not one of them.

[DroughtBuster]

Thanks Bruce. Great video, really interesting. The one thing I would like to know is where on my tank the toilet allows water/waste to enter the tank. If the toilet is at the end away from the dump hole, then I would say my way of rinsing is much more effective than filling from the dump hole and allowing the water to "back up into the tank". The reason I say that is that as the water back flows into the tank, it is pushing the dump material away from the dump hole. If the toilet is at the opposite end, every time I add water to an "empty" tank to rinse it, I am pushing the material toward the hole. I do agree that the tornado gets the sides much cleaner. My RV came with a black tank flush. I plan to use it extensive this week to see if I have better (and quicker) results. Thanks again. Very informative.

[n1282x]

Immediately change your air admittance valve under the bathroom sink

[Mikelff]

Originally Posted by Jason.rhodes86

On week vacation. Emptied tanks Tuesday and then yesterday, Thursday. After doing it yesterday the bathroom has smelled pretty bad, like a porta potty. The seal on the flapper is fine because it’s holding water in between uses. Could just need another dump with a good flush out or two? Any ideas?

I would recommend you switch to a microbial tank treatment like the brand “Unique Digest it” tank treatment. NEVER have had smell issues or blockage issues. It literally eats the poo and TP. It will eliminate poo pyramids. They say in the instructions to NOT flush your black tank unless you are putting it up for storage. Thats the only time I flush my tanks. This product is a liquid and is available from Amazon, Walmart, and several other retailers. I have tested several brands of tank treatments an nothing is better than this product. Follow the instructions and I doubt you will use anything else. Give it a try. Don't try to reinvent the wheel.

[falcondan95705]

Mine did the same thing. The black tank is 2 piece with the top glued to the tank. Mine came undone where they glued it together. Took the bottom off and removed the tank. cleaned it and used abs cement with screen material.

[Mzunrs]

This is the exact issue that I had. Take a picture of the label on the side of toilet. Call the 800 number. I had a new one delivered and was able to install easily and the stank is gone!

Originally Posted by slow

What toilet brand and model do you have?

The Dometic 300 has a known sealing issue between the bowl and base that eventually results in sewage smell.

Google “Dometic 300 problem” for more info.

Dometic may still be replacing them free of charge.

[Cracker]

I've used the Thetford additive every time I've dumped my black tank. I've never had any odors in over 25 years with any of my motorhomes or trailers.

[WDPatterson]

Originally Posted by Jason.rhodes86

Dumped this morning and flushed good before leaving. Got home and smell is still there. Since the smell is getting there from the tank, I guess next I’ll look into the wax seal under the toilet or the ventilation system. Only way I can think smell is getting in. Never had this issue untik this week.

Does your bath / shower empty into the black tank??

[Jason.rhodes86]

Originally Posted by Mzunrs

This is the exact issue that I had. Take a picture of the label on the side of toilet. Call the 800 number. I had a new one delivered and was able to install easily and the stank is gone!

I did. New one is on the way. Gonna try to fix the current one and if it doesn’t work, have new one as backup.

[Jason.rhodes86]

Originally Posted by WDPatterson

Does your bath / shower empty into the black tank??

No, goes into separate gray tank.

[NH_Bulldog]

Originally Posted by Jason.rhodes86

On wait for about 20 minutes but once I finally got thru it was smooth. Replacement on the way should be here in a week. I’m going to try to take the old one apart and use some silicone around the inner seal. I’ve found a few videos where people have done this and it seems to work. Then worst case I jist replace it with new one and hope that one holds.

The issue with my toilet was the inner seal “O-ring”. It is circular, but the gasket is actually square-sided. When the two halves of the toilet are mated, the gasket can roll. I fixed mine and used it for over a year before installing the replacement. I still have the old one as a spare (after I pressure washed it).

[Mollyb]

It could be your atmospheric vent under a sink if you have one.
Replaced mine and it screws in.

[Jason.rhodes86]

Originally Posted by NH_Bulldog

The issue with my toilet was the inner seal “O-ring”. It is circular, but the gasket is actually square-sided. When the two halves of the toilet are mated, the gasket can roll. I fixed mine and used it for over a year before installing the replacement. I still have the old one as a spare (after I pressure washed it).

Do you have the dometic?

[Jason.rhodes86]

Originally Posted by Mollyb

It could be your atmospheric vent under a sink if you have one.
Replaced mine and it screws in.

I’ll check that but fairly confident it’s the toilet. Smell is pretty strong coming from the rear of it