Community Forums

bud01234 · 05-26-2016, 09:40 AM

been full-timing in new (to me) 1998 National Dolphin for about 6 months. Have full hookup and been using grey water backing up in shower as indicator to dump tanks. (black, then grey). The indicator lights have never worked to show tank levels, but the above system seemed to be working fine. After dumping black, dumping grey immediately clears out standing grey water in the shower.

Today, I smelled a stinky odor, and checked the bathroom. I had about 5 inches of very stinky dirty water in the shower. I immediately dumped the black tank, then came back inside to check the toilet before dumping grey. The foul water was GONE from the shower!! huh???

I then dumped the grey tanks and closed both valves as usual. Now I'm in process of cleaning out my shower with Clorox but am really concerned what could have happened. The part about dumping the black tank empting my shower water really concerns me. How could that happen??

Thanks,
Bud

okcnewbie · 05-26-2016, 09:56 AM

I would empty both tanks then leave the gray open and run the shower. One by one verify which drains are plumbed to the gray/black. Never heard of a shower plumbed to black. Very interesting.

mrk · 05-26-2016, 11:44 AM

Five inches of water in the tub is quite a bit of water! Did you use the washing machine, or something else that might discharge a lot of water in a short period of time?

A lot of folks don't realize that 'grey' water can smell as bad, or worse, than 'black' water. If I had to guess, I'd guess that this was a back-up of grey water, and emptying the black tank really had nothing to do with the draining of the water from the tub. It could have been a restriction in the plumbing or possibly the vent, and while you were outside, it co-incidentally "broke loose" and drained into the grey tank, which you subsequently drained, too.

As I read your post, I understand that you are connected to full hookups (includes sewer). Most would leave the grey water drain open so there is no chance of overfilling the grey tank. You can check the black tank from above.

If you happened to NOT have your slinky connected, but rather had the main discharge capped, I guess it's possible to have inadvertently left both drain valves in the 'drain/open' position, and that could allow intermingling of the grey and black waters, but something had to put a lot of water into the system in order for that much effluent to have overfilled the tank. Maybe a kitchen or bathroom faucet left on? Or a leaking valve in the washer?

Let us know how this develops.

bud01234 · 05-26-2016, 11:55 AM

thanks guys,

nothing unusual in water usage (no dishwasher or clothes washer); however DW did a lot of dishwashing and tends to leave the hot water running to rinse all while doing dishes. I could understand filling up the grey tank, but when dumping the black tank, all the standing water in the shower went away before I dumped the grey tank.

I'm going to take your advice and leave the grey open to drain. Only issue I have is having grey water to flush after dumping black. I guess I can just run the shower until it starts backing up before dumping black.

Also, I won't have any way of seeing if the stinky stuff backs up again, but I can live without having to do another hazmat cleanup.

mrk · 05-26-2016, 12:11 PM

It's surprising how much water can pass through a faucet that is left 'on' for any length of time. I'll bet that was the source of the influx.

The black tank is 50 gallons, so I'll bet it would take the better part of a week (maybe two weeks) to fill it up. As it approaches "full", you could go ahead and close your grey water valve for a day or two. That should give you enough water to rinse your slinky. Or you could dump the black tank, close all valves, remove the slinky from the connection in the bay, rinse it with a hose (not your fresh water hose), and re-connect the slinky.

Does the '98 Dolphin have a black water flush connection in the water bay? Although you're supposed to leave the dump valve open when using it, I suspect that, after rinsing the black tank for a while, you could close the valve to accumulate additional water, then open the valve for a purge of the slinky hose.

bud01234 · 05-26-2016, 12:30 PM

Quote:

Originally Posted by mrk

Does the '98 Dolphin have a black water flush connection in the water bay? Although you're supposed to leave the dump valve open when using it, I suspect that, after rinsing the black tank for a while, you could close the valve to accumulate additional water, then open the valve for a purge of the slinky hose.

Now that you mention it, mrk, that's another issue. I used that once and it worked well, but last week I hooked up my non-potable hose to the flush connection, turned on the water, and water started spraying from the connection and no water flowed into the tank. I suspect the check valve may be farkled and blocking input water rather than the other way around.
Of well, that is another issue and not quite as critical as the black/gray thingee.

I guess I should bite the bullet and go get my tanks pumped and have that flush fitting looked at. Some others mentioned that the spray fittings may be clogged but I have no idea how to pull them out to inspect them.

So, in response to your excellent suggestions, In the meantime I think I will leave the grey open until the black tank starts getting full (upon visual inspection), then dump black and fill the grey tank to flush out the hose.

Old-Biscuit · 05-26-2016, 12:38 PM

IF you are going to leave Grey drain valve OPEN......make a dip in sewer hose so that it acts like a 'P' trap.

Otherwise sewer/septic critters (sewer flies) can invade your Grey tank, set up nursery and breed...........plus invite all the cousins to come and stay.

Day before dumping Black Tank....close Grey drain valve and let water accumulate

Personally........I never leave any drain valve OPEN and haven't looked at the level monitor in over 8 yrs.
When toilet 'burps' ----time to dump
When sink/shower drains slow down----time to dump
When pump goes 'burrrrrrup'---fresh water tank empty and I should have added more water

Even with FHU site we use fresh water tank/pump
Waste tank capacity is larger than fresh water tank so when I need fresh water----time to dump tanks
If pump 'cycles'----could mean leak somewhere
And when RV is unoccupied/sleeping----pump off

Had fitting o water heater blow off during night while connected to city water and as we slept the living room/kitchen flooded $6000 Claim
No more of that!

bud01234 · 05-26-2016, 01:18 PM

LOL-Old Biscuit you remind me of somebody.
Sounds like great advice.

Bud

bud01234 · 05-31-2016, 09:57 AM

Disturbing follow-up:

To recap, I originally had about 5 inches of foul smelling water in the shower after DW washed a bunch of dishes. When I drained the black tank first, it drained the shower water at the same time... the grey valve was still shut. I went ahead and drained the grey tank after black and it drained normally but wasn't sure why black dump would remove from the shower.

As suggested, I left the grey valve open (with loop in hose to keep out varmints) anc closed black valve. Everything worked fine for about a week. Today, when taking my shower, noticed water draining very slowly then it stopped. Ended up with about an inch of water in the drain end that stayed there. Exactly as if the grey tank was full.

Went outside and checked and the grey valve was open. Pulled black tank and it dumped normally and sucked out the grey (hopefully) water in the shower.

Never had this happen before and is major disturbing. Is the shower now my signal that the black tank needs dumping?? Not good.

any suggestions much appreciated!

Scarab0088 · 05-31-2016, 10:42 AM

If I am reading this right...it appears that on 2 occasions, the OP has seen that the shower goes into the black tank. This could be true...odder things have happened with used RV's.

I would do a proper test to ensure what is happening...
~First, fully dump and close the dump valves when done.
~Then run the shower...give it a minute or few to get a good bit of water in the tank.
~While the shower is running, go out and open each valve to see what tank receives the shower waste.

I did this for EVERY drain in our new-to-us RV...just to be sure what did what.

Best luck

okcnewbie · 05-31-2016, 11:37 AM

Quote:

Originally Posted by Scarab0088

....I would do a proper test to ensure what is happening...

I think that was suggested about a week ago. That's what I would do as well.

Gordon Dewald · 05-31-2016, 11:52 AM

Good plan. We found out that one of the bathroom sinks is plumbed to the black tank. It is entirely possible the shower has been routed to the black tank to provide "extra" fluid to flush the tank or to provide a better balance between the holding tanks so both fill at similar rates and are dumped at about the same time.

bud01234 · 05-31-2016, 12:10 PM

Quote:

Originally Posted by Scarab0088

If I am reading this right...it appears that on 2 occasions, the OP has seen that the shower goes into the black tank. This could be true...odder things have happened with used RV's.

I think we're on to something but now sure I like it.

I called the DW and had her shut both dump valves (both tanks were empty), then come inside and run the kitchen sink for about 5 min, then go out and dump the gray valve. It dumped normally. She also pulled the black tank and nothing coming out. she then closed both valves again.

Next she went inside and ran the shower for about 5 minutes then pulled the gray dump- NOTHING. she closed it then pulled the black...Dumped the water that had run into the shower.

Bottom line, the shower is plumbed to the black tank. I don't like it but looks like I'll have to live with it. I'll run lots of water to the kitchen sink to get more into the gray tank. Wonder where it will back up to when it (gray tank) overflows? (sigh)

bud

Scarab0088 · 05-31-2016, 12:43 PM

OK...Great job for Mrs. Bud

So you know the issue. This is probably an owner mod...but a smart next step would be to check which tank the bathroom sink feeds(?)

Many makers run the small bath sink to the black tank to allow easy addition of add'l fresh water to the black tank (folks often do not use enough water in the black tank).

If the bathroom sink feeds the black tank, the shower was possibly connected to that drain by the previous owner (not hard to do).

Many, many folks do not use their RV showers...instead going to the campground facilities...so the swap is not a big surprise. It maximizes the grey tank for the kitchen sink, half bath sink, external kitchen, dish washer and washing machine - if so equipped.

Don't know if you want to try to change it, but at least knowledge is power