Black and gray sewer valves open or closed

[Ole_B]

I have a 2016 ventana I store it in a garage. My question is should I store it with the black and gray valves open or closed? Keep in mind I have properly flushed and cleaned both tanks. I have currently stored it with both valves open for about a week. I do live in Phoenix Az so freezing is not a problem. Today I shut both valves which was very difficult. Thanks for your input.

[Farmboy666]

Putting water and some canola oil in doesn’t really make sense, the oil will float on top doing exactly what?

[AllegroD]

I think some of us misread the OP as we were thinking "in use." I would still keep them closed in storage to keep bugs out.

[obgraham]

I do agree, Techwriter, that in the list of things to worry about, this one doesn't amount to anything!

[TechWriter]

obgraham wrote:
The last post doesn't make sense to me. In the OPEN position, the seal is free to flex with changes in temperature. So over a long period of time it might, making it hard to close.

That flat part of the seals is pressed firmly against the valve by the plumbing on either side of the valve. Nothing will flex. Several years in the AZ desert & my open valves still work just fine.

You're inventing a problem where none exists. If you're that concerned, leave the valve 1/2 open.

This reminds me of the used-to-be (hopefully) forum "wisdom" that advised against using bleach in holding tanks because it would destroy the valve seals.

[obgraham]

The last post doesn't make sense to me. In the OPEN position, the seal is free to flex with changes in temperature. So over a long period of time it might, making it hard to close.
In the CLOSED position, the seal is resting on the valve, everything is in the position you want when you're using the tank. Might take a little jerk to open, but it should slide back closed easily.

I'm with the majority here.

[TechWriter]

I guess I'll go against the grain and say leave them OPEN to keep the tanks dry, but use a Vented Sewer Cap.

As far as the gate valve "seals" drying out, I don't think that's a real worry. The seals are Santoprene which is very rugged and the seals themselves are pressed flush against the plumbing:

[AllegroD]

Closed.

[Ole_B]

Thanks Rick, You are right you never get everything out.

[Rick_Jay]

Ole B,

One year, (second or third year we had the RV...still a newbie! LOL) I had the "bright idea" of leaving the valves open during our winter storage. The tanks were well cleaned & flushed. I have a black tank flush kit installed and a clear pipe, so I could confirm everything was clean. Or so I thought.

Apparently sometime during the long winter's nap, I may have adjusted the level of the coach or perhaps the jacks settled a bit. I don't remember the details, I didn't think it mattered at the time.

Well, you guessed it. There WAS some stuff left in the black tank (fortunately not much) and the shift in level of the coach caused it to find the drain. Soooo.....dewinterizing in the Spring was a bit messier than usual. LOL 🙂

So, keep 'em closed. Keep the cap on.

~Rick

[10forty2]

wa8yxm wrote:
Closed, always Closed.
Now you are talking about storage.. I will talk about camping

Ever see the adds in RV magazines for useless expensive chemicals to put in your black tank that show the Stinky RF 5 will get you 10 that he has his gray valve open and the stink is coming from the park sewer system, not his tanks.

That's one of my concerns when on full hookup. If you leave the valve open, you not only don't have enough water in the tank to keep the solids floating/dissolving, but you also have a direct vent into your RV from the sewer system and everyone else's poop.....camping, sitting still waiting for the next trip, storing over the winter.....all valves closed and at least a couple of gallons of water in the tanks and in the traps.

[wa8yxm]

Closed, always Closed.
Now you are talking about storage.. I will talk about camping

Ever see the adds in RV magazines for useless expensive chemicals to put in your black tank that show the Stinky RF 5 will get you 10 that he has his gray valve open and the stink is coming from the park sewer system, not his tanks.

[GHOST1750]

Looks like the "CLOSED" is he winner hands down. I'd vote the same way.

[wvabeer]

I have taken these apart, the seals look like they should remain closed so they will not deform after being open for a long period and then close. That appears to be hard on them. The oil sounds like a great idea. I will do that too.

[Ole_B]

First I want to thank all of you for replying. I appreciate all of your comments. What I will be doing is using a small amount of water in each tank with about 3/4 cup of canola oil. You may ask why canola oil? The answer is because my wife has some almost out of date. Let's all remember we are never to old to learn something.