Horrible Smell - Itasca Sunstar 35F

[oakcreekeric]

Originally Posted by Podivin

Do you have the vent fan running when you flush?
That can draw air from the holding tank into the bathroom.

No.. the fan isn't on while in the act of flushing.. we usually turn it off while using, then back on when finished.. as we are familiar with the tank odors being drawn up via the fan...

[SuperGewl]

Check the actual tank on the 1/2 bath and see if there is a gap between the exhaust vent on the tank and or the actual connection to the toilet.

[oakcreekeric]

Originally Posted by SuperGewl

Check the actual tank on the 1/2 bath and see if there is a gap between the exhaust vent on the tank and or the actual connection to the toilet.

Unfortunately, I have the RV at the shop due to some generator issues we've been experiencing...

Do you know how to access the top of the tank? I was thinking the back wall behind the toilet has some screws.. if not, I know the compartment below has some access, but it will be extremely limited...

I'm thinking the same as you.. there has to be a crack/leak somewhere, as it only happens when we use the toilet in that bathroom..

Another question... Have you ever removed a toilet.. does an RV toilet have a "wax" ring??

The one thing that concerns me.. as I said in a previous comment.. When I drain my black tanks, I continually flush the tanks with clean water.. and while filling the tank, I got distracted and I had bubbles/foam coming out the vent stack (after the initial flush and a clean flush, I add Dawn to the tank for the sensors).. I don't know how full the tank got, but I know it had to be dang close to over flowing.. I didn't see any water coming out from underneath the RV in that area.. that leads me to believe its sealed.. but I will investigate again..

[marjoa]

We have the exact same coach as you only Winnebago. IMO you don't have a blocked vent tube and NO this vent being close to the fridge vent has no bearing.

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

#2
In addition to not venting properly and more importantly—as another person mentioned—this smell comes from bacteria, microbes and what-have-you. I know you said you flush regularly but, I suggest you do a thorough sanitizing of your 1/2 bath black tank using the Geo Method. Look it up. But for right now, right off off the bat:
• drain the 1/2 bath black tank & flush as you normally do
• then...fill that 1/2 bath black tank up all the way full with just water
• add 1/2 gallon of bleach (make sure you flush any extra full strength bleach OFF the toilet flapper seal so it doesn't damage it)
• let this bleach water sit for 24 hrs. in the tank (do not use this toilet during this time)
• then, go to the macerator drain valve and open it
• go to the wet bay and open the 1/2 bath drain valve, then push the macerator pump button for about 5 seconds or so, just so you start to see it start to drain into the sewage hose, then release the button and close the valve.
NOTE: What we're trying to achieve here is not only sanitizing the tank but also the macerator pump, the PVC pipe joints, the hose and the valve. In other words...fill the entire system with this bleach water
• let that bleach water sit in there for another 8 hrs.
• then drain the entire system

Once this is done:
• Add approx. 2 gallons of water, 1 cap of liquid Calgon and one scoop of Happy Camper to the 1/2 bath tank

This should do it. But if not, rinse & repeat. Sometimes it takes 2 or 3 applications for a real fowl black tank.

I'll step out on a limb here and can almost guarantee that this will fix your problem.

Be sure to read about the Geo Method.

Good luck Mr. Stinky.

[FatChance]

We use a lot of water in both of our tanks and don't have any odor problems. Properly maintained tanks don't need chemicals beyond clean water in sufficient quantities in a properly designed system. If you have to use chemicals, there is another system problem or not enough water flushing the tanks.

[69judge]

As a plumber, rv owner and had a similar problem (while driving). I can tell you it's about pressure. The main purpose for the vent is so your tank will not hydrolock during draining. I believe while you are driving, air is pressurized down the vent. As you flush, the room will flood with gasses. If you don't experience any issues other than when you flush, then I do not believe there is a crack or space between the tank and vent. If it were my coach, I would cap the vent with a fernco cap, then simulate the driving conditions. See what happens, its cheap with minimal labor. I will add if temperature increases after the cap is installed, it will act like a gas can bulging in the sun with pressure, if there are no leaks in the system. I'm not sure if there are any rv vent caps on the market that create a vacuum while driving. I will be searching for one myself though to correct my issue.
Wish you luck.

[4x4van]

Here's an option for creating a vacuum on the vent, but only during daylight hours: https://www.amazon.com/Ultra-Fab-53-...solar+vent+cap

[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

[WD5DBV ROY]

This maybe out in left field but I had a really bad smell thought it was holding tank. After some more checking it was shorted battery and the charger was working overtime trying to bring it up and was gassing the battery. Worth looking at your batteries.

[CharlesinGA]

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

Thank you for this comment. I too am experiencing odors when driving and to a lesser extent when stopped. Some of it was because of a very strong quartering tailwind driving across Nebraska. I was driving with the window open and the rear vent open. I closed the rear vent and it practically went away.

I do notice the odor is quite strong directly behind the toilet between it and the wall, and none elsewhere after it sits a while. I was debating pulling the toilet and replacing the closet flange seal, as I am thinking this is where the fumes are coming from. The blade valve seal in the toilet is fine, as it holds water for weeks if you let it sit.

Charles

[soonerdave]

We had this problem in our coach. I checked the air admittance valve under the sink, it was loose and barely screwed in. I wrapped the threads with teflon tape and reinstalled tightly.

Next I went on the roof and changed out the black and gray vent caps and installed Camco 360 vent covers on both vents.

No more odors of any kind. This is a picture of a 360 vent cap, they come in both white and black.

[ladagobago]

we keep the plugs in the sink and put in some water.

[marjoa]

Originally Posted by soonerdave

We had this problem in our coach. I checked the air admittance valve under the sink, it was loose and barely screwed in. I wrapped the threads with teflon tape and reinstalled tightly.

Next I went on the roof and changed out the black and gray vent caps and installed Camco 360 vent covers on both vents.

No more odors of any kind. This is a picture of a 360 vent cap, they come in both white and black.

Attachment 174835

Yep these are the same vents I installed. (see post 32)

[Agility57]

Originally Posted by tacaem

Other problems people are having is the vacuum breakers that are under every sink is leaking and stinking up the coach when moving

^^^ 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.