holding tank smells when traveling

[John P Benz]

Hi everybody, I'm new to this forum. I have a 2005 ultra super c 33 footer. Everything works good except for the black water tank. When I am driving, we have to keep the bathroom fan running to keep the odor in the bathroom! Is this a common problem or is there a cure?
thanks JB

[earljan34]

John, First Welcome to gs owners forum! The first thing I would check is that the vent pipe is not blocked if it is clear then you can install some type of vent cap that draws the smell away like the one they sell at Camping World item #26177 this will work. But first make sure the vent pipe is clear.

Earl

[mfa]

I've got a 2006 of the same model and I have had a few occasions when I thought the smell was more than it should be. Like Earl said, I've heard that a blocked vent pipe can cause that. I know my unit was on the dealer's lot for a long time and I saw mud daubers going in/out of another RV's furnace vent when I was visiting there. I haven't been sufficiently motivated to climb up on the roof and inspect the vent, though. :shock:

If you confirm that's what is causing your problem, maybe that will give me the motivation. :)

[Timothy]

You may have a bad flange or interior seal on the toilet. Does the toilet hold water? If not its probably the plate seal, if it does check the flange bolts to see if they are tight.
If the seal is bad running the fan may pull the odors out of the tank and into the unit.
And as other pointed out check the vent pipe. It may have come apart inside somewhere too, I had that happen on a travel trailer that I owned.
Another thing that may have happened is the vent pipe is too long going in the tank and once there is a certain amount of water it covers the pipe opening, or the vent pipe does not go all the way up to the cap on the roof, you can pull off the cap cover to see.
Let us know what you find!!.......Tim

[hyall]

If your unit sits for awhile you may have to reactivate each fixture trap by adding water to reseal and most of the time the pungence odor is from the grey tank and not the black, we have cured this problem with are travels many times, if not then checked out the vent

[RJ82much]

We have also had occasional sewage smells in the bathroom area while traveling. It seemed as though I usually would find a window or ceiling vent was left open & I assumed a vacuum was formed while moving.

On this trip, the odor was particularly strong. At an intermittant stop, the wife made me tear wall panels, heater panels, everything apart to locate what she felt was certainly a decaying rat. The smell was getting into the kitchen from under the entertainment center (up against the bathroom compartment).

After finding nothing, doing her commanded addition of even more tank deoderant. I put my head under the bathroom lavatory... WHEW what a stench! Out came the screwdriver to disassemble the base cabinet when I noticed a pipe stub coming up from the waste line & ending just under the sink. The pipe was open at the top with internal threads! WaLa - a direct vent from the (grey) tank to the MH interior at a location where many walls meet and are open inside of this base cabinet.

My plan was to purchase an 1? plug to seal the hole. However, the next day, wife remembers a black "thingy" that was loose in the bathroom at delivery. She digs out a "1? vent check fitting". A quick Google search shows that these are used to vent a waste tank when a manufacturer wishes to save the expense of running a vent up a wall & out through the ceiling. They are apparently legal in manufactured homes & RVs. I have to check topside to see if I only have 1 (black-water) vent.

So, to anyone who has odors in their unit, check to confirm there is not an open waste pipe under the bathroom lavatory. It accounts for the smell.

[zzrv]

I had the exact same problem as RJ82much. The inline vent under the vanity was missing. Home Depot has them for about 6 bucks. Solved the problem.

BTW, before I knew what an inline vent was, I was in contact via email with Molly at GS, but haven't heard from her in a month or more from my last email. I finally figured it out for myself after looking under the sink and seeing an inline vent there. Then I knew what was missing from under the vanity.