Plumbing Questions from an IT Guy

seakayaker · 12-02-2016, 11:01 AM

I have the normal black and gray valves to dump. However, I also have another gray valve located near the rear of my TT.

This other gray valve is currently in the "pulled" position. AFAIK that's the desirable position as we've not had any problems after 6 trips.

What is the 2nd gray valve for?

Should it be opened or closed?

In what scenario would I need it in one position or another?

Now you know why I work with computers.

1000 Thanks!

Seakayaker

**Herk7769** · 12-02-2016, 11:19 AM

Sounds like your Wildwood has 2 gray tanks (perhaps one is a remote bathroom or your galley sink). You would need to move your sewer hose to the other gray tank to dump it when it reads full; then back to your normal hook up which most likely has your main bath and shower.

I know some folks have done modifications to connect the remote holding tank to the main dump valve or just laid out some extra hose with a "Y" connector to keep it hooked up all the time.

I personally keep the gray tanks closed (as well as the black) till I am ready to dump just so food scraps, soap, and, hair that make it into the gray tank has some oomph to get rid of it during a dump. Leaving them open allows that stuff to stay in the tank and dry to the walls.

You DO have to monitor your water usage so there is no "shower pan surprise" if you overfill the gray tank, though.

rockfordroo · 12-02-2016, 11:22 AM

Looking at your floor plan, I'm guessing it would be for a 2nd gray water tank for your kitchen sink. (One in front of the axles for the bathroom and one behind the axles for the kitchen.) I'm assuming it is hard piped into the final sewer drain? If it is piped into the final drain and if the valve has always been open, I'd say you've been "dumping" your kitchen gray tank to the sewer drain at all times. If this is so, I'd expect you'd have gotten some water out of the sewer drain when you removed the cap to hook up the sewer hose, as I doubt the tank would have drained "completely" the last time you were hooked up, and then driving down the road would have sloshed whatever was left into the drain line.

I'm thinking it must be hard piped, because if it wasn't, and the valve was open, you should have been dumping your kitchen sink water onto the ground, which I think you would have noticed on your first trip!

Does your control panel have tank level readouts for 2 gray tanks? I would think it should.

seakayaker · 12-02-2016, 11:23 AM

I'm fairly certain that I don't have a 2nd gray tank. On the last day of a trip this summer as we were cleaning up getting ready to leave, the kitchen sink began to back up. When I dumped the gray tank, it emptied.

Will definitely check to make certain there's not another tank back there but I don't think so. Don't see but one place to connect the sewer hose.

bshort · 12-02-2016, 11:33 AM

I have a galley tank and the sewer hose connection is quite higher than the blk/gry connection. I actually have to get on a knee and somewhat crawl under the slide to connect it. You definitely wouldn't see it unless you were down low.

rockfordroo · 12-02-2016, 11:40 AM

Quote:

Originally Posted by seakayaker

I'm fairly certain that I don't have a 2nd gray tank. On the last day of a trip this summer as we were cleaning up getting ready to leave, the kitchen sink began to back up. When I dumped the gray tank, it emptied.

Will definitely check to make certain there's not another tank back there but I don't think so. Don't see but one place to connect the sewer hose.

If there's only one place to connect the sewer hose, then you have one of two things:

1. A galley tank behind the axle, hard piped into the sewer connection

OR

2. The kitchen sink is hard piped into the gray water tank in front of the axles.

I believe #1 is more common than #2 simply because the drain line would mostly likely have to remain higher than the single gray water tank; but I could be wrong.

Also, your kitchen sink appears to be on the opposite side of the TT than the bathroom stuff so that also makes me think you've got 2 tanks.

If they didn't tell you about all of this on your PDI, shame on the dealer.

Let us know when you figure it out.

seakayaker · 12-02-2016, 11:50 AM

Quote:

Originally Posted by bshort

I have a galley tank and the sewer hose connection is quite higher than the blk/gry connection. I actually have to get on a knee and somewhat crawl under the slide to connect it. You definitely wouldn't see it unless you were down low.

The plot thickens...

Looks like I do have a 2nd tank. It is listed on the control panel. This valve is downstream from it and has always been open (new TT came with it open. I never touched it).

There doesn't appear to be a separate connect for the sewer hose. I see only one connect for the sewer hose. It's the one I always use to dump (black valve first, then gray). When I connect the sewer hose I never get wet from water coming from the galley. I guess there could have been a few drops but I can't recall ever seeing any water while connecting the sewer hose.

I've always kept the two main valves closed until dump time and no errant water has been dumped elsewhere.

What would be the purpose of this 2nd valve? Seems closing it would just isolate the galley tank. Why?

seakayaker · 12-02-2016, 12:00 PM

I'm new to this so be gentle...

Is the purpose of this valve so that if you're boondocking you can isolate the galley effluent to it's own tank so as not to fill the main gray tank so soon?

Would it also be useful when camping at campgrounds with dump stations so that you don't have to dump as often because galley effluent is it its own tank and shower water is in the other tank?

325BH · 12-02-2016, 12:38 PM

Quote:

Originally Posted by seakayaker

I'm new to this so be gentle...

Is the purpose of this valve so that if you're boondocking you can isolate the galley effluent to it's own tank so as not to fill the main gray tank so soon?

Would it also be useful when camping at campgrounds with dump stations so that you don't have to dump as often because galley effluent is it its own tank and shower water is in the other tank?

I can't speak to your rig, however my TT has three tanks: 1 black and 2 gray.

Each tank (3) has its own valve and handle.

There are two discharges:
One is shared by the black tank and 1 gray tank that services the bathroom. (This is forward of the rig.)
The other is for the 2nd gray tank that services the galley sink.

I would look for a second discharge. If you really only have one hose connection, then the extra valve you found must be dumping into the one shared discharge... and have been draining your 2nd gray tank all the time. Since it has its own valve, I would expect it to dump straight into the shared discharge and not a tank (if it doesn't have its own discharge). Surely you would have noticed a full discharge pipe when you removed the cover? Have you been putting water into the 2nd gray tank?

rockfordroo · 12-02-2016, 01:27 PM

If you don't have an enclosed underbelly, you should just be able to lay down under the TT and follow all the piping around.

Note that the gray tank drain lines are usually 3" dia. and the black is usually 4" dia.

I've attached a sketch of typical drains.

**bikendan** · 12-02-2016, 01:36 PM

sea kayaker, your dealer sure did a very poor PDI for you.
Between this and them not explaining how your furnace works, that's two major fails of something every PDI should cover.

DrLewie · 12-02-2016, 01:46 PM

And my fiver has 1 black and two grey tanks, each with its own flush valve, but all are combined into one sewer hose outlet. One grey is for the kitchen and the other is for the shower. After 5 years if RVing, I still haven't figured out where the bathroom sink empties. Anyway, I've handled all tanks the same way. I keep all closed when camping. On dumping I first empty the black tank, then the sink tank, which helps wash out the drain hose, then the shower tank which finishes the job. The issue of open or closed tanks while camping is one of those things that there are two opinions about, but I go with the theory that the solids from the black tank empty better when there's a bunch of water in there, and that the spurt of grey water helps wash out all the pipes and the hose.

rockfordroo · 12-02-2016, 02:06 PM

Quote:

Originally Posted by DrLewie

And my fiver has 1 black and two grey tanks, each with its own flush valve, but all are combined into one sewer hose outlet. One grey is for the kitchen and the other is for the shower. After 5 years if RVing, I still haven't figured out where the bathroom sink empties. Anyway, I've handled all tanks the same way. I keep all closed when camping. On dumping I first empty the black tank, then the sink tank, which helps wash out the drain hose, then the shower tank which finishes the job. The issue of open or closed tanks while camping is one of those things that there are two opinions about, but I go with the theory that the solids from the black tank empty better when there's a bunch of water in there, and that the spurt of grey water helps wash out all the pipes and the hose.

Put some food dye down the sink next time you're camping and see which tank it comes out of.

I'm assuming you have a clear connector, either straight or curved, like this one so you can see what's coming out.

ChipBruce · 12-02-2016, 02:54 PM

It seems that if the tank was open for 6 trips there would have been a lot of water and food chunks on the ground that would have been hard to miss. Is this maybe the fresh water drain valve instead? If seakayaker has not used the freshwater tank then that is a very real possibility. Just a thought.

bbcutright · 12-02-2016, 03:27 PM

My valve is for the outdoor kitchen sink....

markb422 · 12-02-2016, 03:44 PM

Do you have heated tanks? The reasson for the second valve, weather you have 3 tanks or not, is so stuff is not sitting in the pipe between the tank and dump valve. If you are camping in below freezing temps the stuff in the pipe between could freeze as the tank heaters do not heat the pipe. You can imagine what a mess that would be to have a froze solid outlet pipe.

itat · 12-02-2016, 05:29 PM

At about 6:30 in this video they show the tank outlet and it looks like it's plumbed so that the galley grey tank connects to the drain on the forward grey tank. So they only have a single valve for both grey tanks downstream of the Y where they are connected.

https://youtu.be/fT1CuWaS92w

buffalohunter · 12-02-2016, 06:03 PM

Wouldn't be nice if all of manufacturers made a video similar to the one that itat referenced. The video had room for improvement but it is a good start for a PDI video that could be referred to by all purchasers or interested buyers.

rockfordroo · 12-02-2016, 06:05 PM

I updated my RV drain pic for this "new" version.

(I'm assuming there's another valve somewhere that we can't see, probably at the discharge of the rear tank. I'm assuming that's the valve you've said has always been open.)

itat · 12-02-2016, 06:47 PM

Rockfordroo, I don't think the OP's setup has a valve on grey tank #2, just the single valve at the outlet.

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