Which one is the blackwater vent. 2015 38Q

arneinfloria · 08-22-2015, 01:23 PM

I want to attach a venturi vent to the blackwater vent on the roof of my 2015 Itasca 38Q. Unfortunately there are three vents up there, and I am unable to tell which one is the backwater one. One would thing the smell would give it away, but the tanks are empty, so that does not work. I looked at the plumbing drawings at winnebagoind.com but that was not helpful.

Any suggestions?

Nomad Mike · 08-22-2015, 02:21 PM

Looking at page 4 of your plumbing diagram, it appears the most aft vent would be the black tank vent.

grtharris · 08-22-2015, 02:23 PM

arneinfloria, it is the one closets to the rear.

arneinfloria · 08-22-2015, 02:28 PM

Thanks!! Where did you find that great picture?

grtharris · 08-22-2015, 02:43 PM

arneinfloria, They are on the Winnebago web site. Here is a link to get started with.
Winnebago Industries
The electrical and plumbing diagrams are 2D and the parts catalog are 3D for 2011 and newer. You have to load some software and do a little tweaking to get the 3D to work. Also on the parts catalog page is the service parts list which will show all of the parts used to build your coach. Lots of good stuff.

wa8yxm · 08-22-2015, 06:40 PM

Remove vent cover and run water down the pipe inside.. If it runs out into the drain hose with the black vlave open that is the one you want. (use a clear section/extension so your partner can see it flow)

bsamole · 08-23-2015, 07:53 AM

The quickest way is to smell each vent it will be obvious. Warning sit down while smelling as the aroma is strong.

arneinfloria · 08-23-2015, 02:55 PM

Great suggestions. It is the one to the rear.

Dfreiberger · 08-27-2015, 06:24 PM

I have a 38Q as well and am curious why you want a vent vane on your black tank. I am asking because I get sewer odors every time I come out of storage to camp. I flush throughly after camping. I have tried leaving some fresh water in the bottom of the tank with chemical packs and no luck. I have tried draining rinsing, and leaving empty and still no luck. One day I will crack the code. Also, isn't the venturi only good when going down the road?

arneinfloria · 08-28-2015, 04:59 PM

The venturi works well when there is a breeze.

We have been annoyed by the smell from the blackwater tank. Tried all kinds of chemicals. No effect. Then I did an internet search. The secret is to use LOTS of water when you flush, and to hold off dumping until the tank is at least half full. This trick actually works. We no longer have a stink problem.

NeilV · 08-28-2015, 10:32 PM

Usually rank smells in the coach when you leave storage is from the water evaporating from your traps allowing stagnant grey tank oder to vent into the coach with the washing machine trap many times being the worst offender. Grey water tanks do accumulate food waste over time and can stink worse than the black tanks after a bit of storage time since most folks don't add any treatments to them. On a few coaches sometimes a sink or shower are tied into the black tank too.

Dfreiberger · 08-29-2015, 05:57 AM

I am only talking black tank odor. The coach smells fine during storage. Only when flushing. Maybe the Venturi could help purge odor when I drive out of storage before using the coach?

C-PHartley · 08-29-2015, 06:46 AM

Quote:

Originally Posted by Dfreiberger

I am only talking black tank odor. The coach smells fine during storage. Only when flushing. Maybe the Venturi could help purge odor when I drive out of storage before using the coach?

Is the bath vent fan on when flushing? If so, try turning it off while flushing. This will stop any vacuum air flow from black tank roof vent, thru the tank, and out the fan vent. I hope this helps.

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