Fresh water going to black water tank, nothing dumps

[poihths]

2018 Leprechaun 31FS.

Attempted to fill the freshwater tank. Connected the hose to the white tank fill inlet. Set the blue lever to "tank fill / winterize" not to "city water". Checked all the valves in the cabin we could find to open. Ran water slowly, listening carefully. After a bit checked the tank levels, which started out all empty. Found the black water tank at 1/2. Went and opened all the dump valves. No flow. So what in the world?

[Mr. Dan]

Originally Posted by poihths

2018 Leprechaun 31FS.

Attempted to fill the freshwater tank. Connected the hose to the white tank fill inlet. Set the blue lever to "tank fill / winterize" not to "city water". Checked all the valves in the cabin we could find to open. Ran water slowly, listening carefully. After a bit checked the tank levels, which started out all empty. Found the black water tank at 1/2. Went and opened all the dump valves. No flow. So what in the world?

Unless my old eyes have failed me, it appears that connection is labeled “Tank Flush”. In most cases, that’s a black tank flush which would fill the black tank, right? Seems like “Inlet” would be a better choice.

[camper_Lucy]

x2 you are hooked up to the Black tank Flush in that photo, thus water in the Black Tank. You are the first to have done that, I am guilty myself of not reading the label the first time I hooked up our new unit.

[cboss]

Originally Posted by camper_Lucy

x2 you are hooked up to the Black tank Flush in that photo, thus water in the Black Tank. You are the first to have done that, I am guilty myself of not reading the label the first time I hooked up our new unit.

I think you mean "not the first".
Hook the hose to the input on lower right labled "Inlet" and all will work correctly.

[bikendan]

Yep, hose is clearly hooked into the black tank flush, not the city water connection.

Sent from my SM-G781U using Forest River Forums mobile app

[poihths]

Yup, I see that now. But how come the black tank won't dump? Solve that and I've got this thing licked! Yes

[cboss]

Originally Posted by poihths

Yup, I see that now. But how come the black tank won't dump? Solve that and I've got this thing licked! Yes

I hesitate to ask this, but do you have the dump valve open? A pic would help.

[poihths]

Well, I would say we have the dump valve open, but my confidence is a little shaky just now! So here's a photo. Black tank shows 1/3 full. And I seem to have three valves on the dump fitting, which I also don't understand.

[bikendan]

RVUSA specs say only one gray and one black tank. But there could have been a mid-year change:

https://www.rvusa.com/rv-guide/2018-...-311fs-tr33229

Sent from my SM-G781U using Forest River Forums mobile app

[Capacitor]

What a mess! Is that mud on everything? It appears that the two on the sides are small so possibly two grey tanks. The one that is open is probably the black.

[Reverse_snowbird]

I have a slightly different idea. Those two handles on the side look like factory installed valves. The one in the back, top, looks like an aftermarket valve meant to stop 'leaks' as you drive down the road. Usually they are installed at the end of the pipe, but considering how low that connection is, it's possible that they cut the pipe and installed it behind the valves.

You need to figure out which valve is for each tank. I'd suggest that you put the hose where it belongs and turn on the water. Then have someone run water in the sink. Then open the valve on the top and then either of the side valves and see if you get water. If no water, try the other valve.

One other thing... do you have another compartment on the side of that rig that might contain drain valves?

One other piece of information. When you're running water into that black tank flush, the valve should be open to drain the tank... once you figure out which is the black tank valve.

[DougW]

Originally Posted by poihths

Well, I would say we have the dump valve open, but my confidence is a little shaky just now! So here's a photo. Black tank shows 1/3 full. And I seem to have three valves on the dump fitting, which I also don't understand.

Based on the diameter of the pipes and the color of the handles, the two on the sides are grey tanks, the one farther back and in the middle is a black tank.

As far as the black tank showing 1/3 full, if you’re talking about the lights on th tank gauge, those are notorious for showing more in the black tank than it actually has in it.

[PopFla]

Your toilet is on the passenger side. Most rigs of that type have the black tank and an additional valve on that side. When that valve is closed, it prevents dumping....stuff....all over the road if the pipe that runs to the dump fitting on the driver's side gets broken by road debris. Take a good look under the passenger side for another valve.

[Qwkynuf]

Originally Posted by DougW

Based on the diameter of the pipes and the color of the handles, the two on the sides are grey tanks, the one farther back and in the middle is a black tank.

As far as the black tank showing 1/3 full, if you’re talking about the lights on th tank gauge, those are notorious for showing more in the black tank than it actually has in it.

Also, that's a 4 year old rig, and the posts from the OP seem to suggest that it it new to them. If both of those are true, it's entirely possible that they are dealing with a clogged drain - maybe even a dislodged 'poop pyramid'.

I agree that it looks like the black drain runs straight back (from the photographer's perspective) and that there are two freshwater drains coming in from each side. If they ran water into the tank flush, then there should definitely be something liquid in that tank. I would probably start by hooking up the drain hose (with a clear elbow so that I could monitor for progress), and then open and close that black handled valve quickly several times to see if something changes. I would probably avoid doing anything that adds more liquid to that tank until I could get at least a trickle out of that pipe.

Side note - I also would *not* be messing around with the black tank drain with no hose attached and that valve open. The way my luck runs, the clog would let go right as I was peering up inside of there.

[poihths]

Originally Posted by Capacitor

What a mess! Is that mud on everything? It appears that the two on the sides are small so possibly two grey tanks. The one that is open is probably the black.

Yup, that's mud on everything. We live quite a ways from the nearest paved road.

[camper_Lucy]

Originally Posted by camper_Lucy

x2 you are hooked up to the Black tank Flush in that photo, thus water in the Black Tank. You are the first to have done that, I am guilty myself of not reading the label the first time I hooked up our new unit.

ops, should have read: You are not the first to have done that

[Tom48]

Originally Posted by poihths

2018 Leprechaun 31FS.

Attempted to fill the freshwater tank. Connected the hose to the white tank fill inlet. Set the blue lever to "tank fill / winterize" not to "city water". Checked all the valves in the cabin we could find to open. Ran water slowly, listening carefully. After a bit checked the tank levels, which started out all empty. Found the black water tank at 1/2. Went and opened all the dump valves. No flow. So what in the world?

I did that once. Pretty sure you were on the black tank flush. Even inlet position, the right hand inlet being right under the selector valve suggests that

[Tom48]

Originally Posted by poihths

Well, I would say we have the dump valve open, but my confidence is a little shaky just now! So here's a photo. Black tank shows 1/3 full. And I seem to have three valves on the dump fitting, which I also don't understand.

So, first question has this tank system ever been dumped before? At times during manufacturing a 3-in diameter cutout from the side of the tank can fall into the tank and then flow to the exit pipe and with a buildup of toilet paper block dumping from that point on.

To rule that out I would leave the valves open and pump water in the left hand fitting which we've established is your tank flush and see if any water is coming out. If no water is coming out double check under the bathroom sink for the breather valve to make sure that you're not bowling water out inside the coach from a failed and a siphon valve.

Ultimately with the tank open and water going into the tank through the black tank flush the water has to come out somewhere.

[D W]

From the pic it looks like it's a straight shot to the black tank gate valve. Shine a light in there and see if that gate valve is open or if the gate valve has been separated from the pull handle and isn't opening.

[CaptnJohn]

I’d clean the mud off the gray tank valve handles 1st. Then put water in the FW tank , already enough in the black tank. Clean mud off that one too. Add water to gray tanks then pull black before both gray, 1 at a time.