Tank vent questions


We have a 6 month old 2022 Sundance 293rl and now since dewinterizing ( in NH) there is a musty smell in trailer. Tanks were cleaned and flushed but I did again but smell returns. Made sure to use flush system to make sure the tanks is clean. But I am told by wife that smell is still there. I went to roof to look at vent pipes and the one for the black tank is very low down and actually offset from the vent cover opening. I think that the smell is venting and some of it is getting into attic and lingering. My question is how is the vent pipe attached to the tank? Did it slide down because it is not properly fitted to the cover? Can I pull it up or should I try to lengthen it and either way should I seal around it to prevent smell from getting into attic area. I have read other posts on here of smell’s traveling back down into trailer.


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Staff member
Yeah that vent pipe looks pretty short. You might want to add a couple inches.
That vent pipe has a mushroom cap for it right?
If you have a musty smell it sounds more like you have a water leak somewhere and it's starting to mold. Check all caulking and feel around for damp spots.



Thanks, yes there is a cap. I can't smell the smell but wife can. It is same as she smells if toilet is opened ( tank is clean and only treated water in there.) I will lengthen the pipe, I'm afraid to try to pull it up in case I pull it out of tank


Prolifically Gabby Member
If you can pull it out of the tank, you have another problem. It should have been glued in place at the top of the tank. If it’s not, you will continue to get odors until it’s sealed.

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Prolifically Gabby Member
First thing I'd do is remove the basement walls to get a look at the black tank. You may be able to see if there is a problem with the drain or the vent connections without too much difficulty. Something else that can stink up a rig is a dead critter, like a mouse or chipmunk. The little devils get inside, can't get out and starve to death...leaving a stink for some time. You mentioned it being a musty smell. That could be due to water (rain, road spray, or the dreaded plumbing leaks) getting inside and doing its thing on wood structures. A leak or gas from the black tank will have its own unique smell.