Holding tank odor

[Andy Illes]

I'm stumped.  Been getting holding tank odors inside Fred whenever I'm running (never parked)... from WHERE?!?!?  I know my toilet-tank seal is good and the bowl holds a good water seal.  I've also checked someone's tip about a gap in the vent-stack... nada.  Is a gap in the vent-to-tank seal possible so the odor's coming through the floor?  Can't see how to check that one.

Should add I don't have caps on my vent stacks... thanks to a curb-side killer tree in NYC (probably planted by The Mad Stapler on vacation), but I don't run with my rear hatches open.

I'm stumped..... ideas/suggestions please?

Thanks all.... Andy

[Shayne]

I put a 90 degree elbow on my sewer vent, opening toward the rear.

I did that after seeing this....

http://www.campingworld.com/browse/skus/index.cfm?deptID=&subOf=19&skunum=26177&src=TSC

After that I never had trouble with oders while going down the road, even when the kids used the toilet while we were cruising down the highway.

[Andy Illes]

Hi Shane.... thanks.   Did you use just a regular PVC elbow?   Seems like an easy 'nuff fix.... but I'm still curious where the odor's getting in in the first place though.  I'd rather fix both.

Thanks again, Andy

[Shayne]

Yeah, just a regular 90 degree elbow.  I think it was 1.5" PVC.

As far as where the odor is coming in, it might just be the pressure being created in the tank blowing air bubbles past the seals.  Maybe you should slow down and keep it under a hundred  

[Conrad]

do you get the oder with the windows up or down?, driver & passenger windows....  I noticed same and concluded that the low pressure at my window(s) was sucking up the smell.

[Andy Illes]

Shayne.... How the heck could I ever get anywhere slowing down that much?!?!?!?  

Conrad.... Don't think I ever noticed it with windows up and I've wondered about "suction" too.  During times I'd smell it, I've cracked the bathroom hatch just barely open to see if that would draw it out, but that didn't seem to make much difference.  Guess I just need to back off the bean burritos, huh?

[Richard Peterson]

Andy,  Check my post of 25 May.  I discovered this source of holding tank odor quite by accident.  You only have to lift up the cover through which the vent pipe go's to the roof to find the joint that separates and leaks the terrific odor!  Hope yours is that simple too.

[Andy Illes]

Richard....  I did see your post and think I responded.   Mine isn't missing that piece, all the connections seem good and I couldn't even jiggle the pipe.    I haven't crawled underneath yet to see if the connection to the holding tank's ok though.   Can't figure what else it could be.

[Richard Peterson]

Andy, you may have to drop the holding tank to see if the seal is any good.  The original putty has pretty much dried up by now.  It is not that bad a project and might make sense if it's never been done.  Use silicone calk to seal it when you put it back in place.  

[Andy Illes]

Thanks again Richard..... that's onna those things I've been putting off.  As far as I know, the tank-to-vent joint's never been redone, and it's the only place I can think of the odor could be coming from.  I know the toilet flange seal is good and as I've said, unlike yours, my connection in that "box" is solid.  I've watched the bowl during pretty heavy winds, when the odor was present, and didn't see any bubbling.  So guess it's time to get under there and check that connection, huh?

Whaddaya think of using Kool-Seal (roofing) putty?

[Richard Peterson]

Wow!  Sure has been a long time since I checked things here.  I guess Kool Seal would work but the silicone in the tubes is a lot easier to use.  Hope you have solved this problem by now.