Horrible Smell - Itasca Sunstar 35F

[oakcreekeric]

Originally Posted by marjoa

We had a very similar issue as you until we did these 2 things:

#1
We've changed out both of our bath vents to the 360's. The OEM vents are notorious for not venting properly. They don't create enough upward draw. The 360's create a much better draft to "PULL" the gases out the stack whether underway or sitting still.

Here's a link that shows one of the new vents installed when I redid our roof:
http://www.irv2.com/forums/f258/fina...ne-316925.html

I'm going with the first part, I think it may be my vent covers.. I'll be honest.. my GF usually gives me grief about the time it takes me to dump my tanks (no, I don't make people wait in line behind me).. She always teases me about doing a "taste" test on my tanks before I officially say I'm done.. I'm pretty anal about cleaning those suckers out.. and besides.. I don't have the issue unless I'm driving and I haven't dumped...

I think changing out the vent stacks will be the way to go

Thanks

[oakcreekeric]

Originally Posted by TCollins

You asked about a wax ring on the toilet. As far as I know they don't come with a wax ring. Any rv toilet I am familiar with has a foam type ring that does the function of a wax ring. They are easy enough to check. A couple nuts need to be removed, water line disconnected and the toilet will lift off.

I was having odor issues from black tank and found the ring had been installed upside down and partially pushed down the hole. It was not making a good seal. I bought a new seal, installed it properly and the smell was gone. Perhaps yours has dislocated or deteriorated. Not fun but a cheap, easy repair.

TC

Thanks for the info.. It may be worth taking apart for the piece of mind knowing it was done correctly...

As I've said before..we only have this issue while driving and we don't have this issue on the back toilet, just the front one..

[oakcreekeric]

Originally Posted by Agility57

^^^ This. I replaced mine after having the exact problem you describe and problem gone, windows open when driving or not. Get a better quality vent cap at your local hardware to replace the cheap one on your rig. I thin I paid $20.00 for mine.

I don't think its the vacuum breakers, as I don't have the smell unless I use the toilet in the middle bath.. However, I may be replacing them as a matter of general maintenance and upgrades..

Thanks

[J2Jake]

Go with the "Turtle" roof vents. Have used them on all the RVs we've owned. We do add chemicals to our gray water tank. It the only tank we have an occasional problem with.

[TCollins]

While you are changing your vent caps take a look at the vent pipe itself. Sometimes for whatever reason they may terminate slightly below the roof line and fumes can be sucked back in that way. Both of my vent pipes were below the roof line. I made a couple short extensions to bring them slightly above the roof.

TC

[Jyrocharlie]

https://www.rvpartsnation.com/rv-plu...ng-tank-vents/

[billdreamlv]

OK, I'm not a plumber but I do know some things about physics, and I did sleep at a Holiday Inn once.

I have had the same thing happen to me. It only happens when I drive down the road. Not when stationary.

Well here is what I think your problem is.

When you drive, the black water in the tank moves around the tank and creates pressure pockets of air that need to try to escape the tank. It is like shaking a plastic gas container full of fuel. Regardless of the size of the vent pipe, these pockets of pressure try to escape some how. That gas under pressure, will exit the vent pipe and increase the pounds per square inch in the vent pipe, sink pipe, studor valve, the wax ring, toilet seal, and anything else connected to the tank. Then, the on the next corner the black water moves again in the tank and sucks air from the vent pipe and lowers the pounds per square inch. This back and forth movement of black water causes gases to escape at the least secure plumbing fitting. YOUR STUDOR VALVE is probably the least secure and some valves will belch gas under pressure.

The solution is to get the most expensive Studor valve and use teflon tape to secure it. Secondly, it might behoove you to cap off the vent and induce a fog or colored smoke in pipe under pressure so you can see where the weak points are. I just replaced my wax ring (it is actually some kind of plastic and fabric) on my toilet and that helped a lot.

Bottom line is that when you are driving with a boat load of ___t, your going to get some gas under pressure. Empty your tanks before you leave. No metaphor here.

[Russ Silber]

I installed directional vent syphones on roof stacks solved problems.