Black tank mysteriously filling

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Blaise

Well-known member
Joined
Mar 2, 2013
Posts
120
Location
Upstate NY
We have a relatively new 5th wheel - a 2023 Grand Design Reflection 311 BHS that we purchased in Sept of last year. This rig has 1 and 1/2 bathrooms, 2 black tanks (one for each bathroom) and 2 gray tanks (one for the kitchen sink and one for the main bathroom sink and shower). The gray water from the 1/2 bath sink and the outside kitchen sink both go in the second black tank.

We have taken it on a few trips, but we've always had city water - never really had the occasion to use the water pump. Well, I sanitized for the upcoming season today. I put 5 gallons of chlorinated water in the fresh water tank via "power fill" - connected one end of a hose to the city water inlet, the other end in a 5 gallon container with the bleach solution, and used the water pump to draw the water into the fresh water tank.

I then connected the city water to a hose bib and proceeded to fill the fresh water tank. When I saw the tank was full, I changed the valves from "power fill" to "city water". I did this because the hose bib is pretty far away and I didn't want to run over there to turn the water off. I figured while set for city water, water would only enter the system if a faucet was open. By mistake, I went around and ran water in the sinks/shower/toilets, but because the system was set to city water, the chlorinated water in the fresh water tank was not being used.

SO ... I turned off the hose bib, turned on the pump and ran the chlorinated water from the fresh water tank through every thing again. I noticed that even when nothing was open, the pump never went off. Thought I had a serious leak, but I could see no other sign of it. Then I noticed that the 2nd black tank was 2/3 full. I know I emptied and rinsed all the tanks for winterization in the fall.

The pump is still running - never going off - while I'm thinking about this and looking for a leak - but then I saw that the 2nd black tank was now FULL. I turned the pump off and scratched my head ...

I DEFINITELY did not connect the water hose to the blank tank flush inlet. (1) water was coming out of the faucets, and (2) the black tank flush inlet for the second tank is nowhere near the fresh water inlet.

I also did not run anywhere near enough water in the outside kitchen and half bath sinks to fill the 2nd black tank (it hods 40 gallons).

I am at a loss to understand what the heck is going on. The 2nd black is now VERY full - if you open the toilet flush valve (with no water pressure) you can see the water level in the tank - right up to the neck of the pipe going into the tank.

Anyone have a theory about what I'm facing here? In the mean time I have to go remove some water from that 2nd black tank!

Nautilus-Water-Control-Console.jpgTank-Flush-Inlets.jpg
 
If I understand you right, the 2nd black tank is filled from the rear toilet, rear sink and outside sink.

There are only 4 ways (in theory) that water can get into this tank. One of the sources above or the rear black tank flush.

Since you didn't connect to the rear flush, it must be one of those sinks or the toilet OR something else is "misplumbed". If it was the toilet constantly running, then it would overflow unless the ball valve is also leaking (seems like you could see/hear it running).

I think you would also know if a sink were running down the drain.

Is it possible that there is a gray tank flowing into the black tank at the dump valve? In other words, does this tank share a dump valve with a gray tank and maybe one is leaking through the dump into another?
 
I agree .. The proper way to plumb the only "inlets" to the black tanks are the toilets and the flush connector. If you are not connected it should not be filling.
However some connect sinks to them as well (There is an argument for that) especilly "Bathroom" sinks. Also the pump running constantly is a clue.. My guess is you left a faucet running on one of the sinks. But I stress the word GUESS.

Three classes of waste water
Black: You know where that comes from
GRAY: Kitchen sink makes it gray due to food particles.
Wash.. Other sinks.. Washing machine. >Shower
 
We have taken it on a few trips, but we've always had city water - never really had the occasion to use the water pump. Well, I sanitized for the upcoming season today. I put 5 gallons of chlorinated water in the fresh water tank via "power fill" - connected one end of a hose to the city water inlet, the other end in a 5 gallon container with the bleach solution, and used the water pump to draw the water into the fresh water tank.

I then connected the city water to a hose bib and proceeded to fill the fresh water tank. When I saw the tank was full, I changed the valves from "power fill" to "city water". I did this because the hose bib is pretty far away and I didn't want to run over there to turn the water off. I figured while set for city water, water would only enter the system if a faucet was open. By mistake, I went around and ran water in the sinks/shower/toilets, but because the system was set to city water, the chlorinated water in the fresh water tank was not being used.

SO ... I turned off the hose bib, turned on the pump and ran the chlorinated water from the fresh water tank through every thing again. I noticed that even when nothing was open, the pump never went off. Thought I had a serious leak, but I could see no other sign of it. Then I noticed that the 2nd black tank was 2/3 full. I know I emptied and rinsed all the tanks for winterization in the fall.

The pump is still running - never going off - while I'm thinking about this and looking for a leak - but then I saw that the 2nd black tank was now FULL. I turned the pump off and scratched my head ...
We also have a Reflection with the the Nautilus water control panel, but just one black tank. My first reaction is the same as SC5thWheeler. But the fact that this is your first use with this configuration raises the question if things ever worked correctly.

If you find a solution before anyone here comes up with it, please come back and let us know. Thanks.
 
Are you still covered by a warrantee? If you are, take it back to the dealer and ask them to run through everything with you watching and asking questions. You could also have someone film it on a phone
 
OK, this is embarrassing ... @SC5thWheeler you hit it right on the nose.


I actually remembered that I had forgotten to run water through the outside kitchen sink, but I figured it could wait until I solved this problem. I mean to do that, I'd have to run the pump, which would put even MORE water in the black tank.

And then it clicked ... the outside sink faucet had been left open by whoever (at the dealer's) winterized the rig. And so it was running the whole time the system had any pressure (pump or city water).

Good grief!! OK, it could have been a lot worse ... the only damage was to my pride!!

Sorry everyone ... but thanks for responding.
 
OK, this is embarrassing ... @SC5thWheeler you hit it right on the nose.


I actually remembered that I had forgotten to run water through the outside kitchen sink, but I figured it could wait until I solved this problem. I mean to do that, I'd have to run the pump, which would put even MORE water in the black tank.

And then it clicked ... the outside sink faucet had been left open by whoever (at the dealer's) winterized the rig. And so it was running the whole time the system had any pressure (pump or city water).

Good grief!! OK, it could have been a lot worse ... the only damage was to my pride!!

Sorry everyone ... but thanks for responding.
Thanks for the feedback, glad you got it fixed. Don't feel embarrassed about anything: We've all made mistakes, some of us have made numerous ones. I've never told anyone that, when we bought the Reflection (after approx 30 years of prior RVing in 2 motorhomes), I hooked the site water to the black tank flush inlet (with the drain closed) instead of the fresh water inlet; They're clearly labelled in your photo, but not so in our Nautilus panel. :eek::oops:
 
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OK, this is embarrassing ... @SC5thWheeler you hit it right on the nose.


I actually remembered that I had forgotten to run water through the outside kitchen sink, but I figured it could wait until I solved this problem. I mean to do that, I'd have to run the pump, which would put even MORE water in the black tank.

And then it clicked ... the outside sink faucet had been left open by whoever (at the dealer's) winterized the rig. And so it was running the whole time the system had any pressure (pump or city water).

Good grief!! OK, it could have been a lot worse ... the only damage was to my pride!!

Sorry everyone ... but thanks for responding.
More than once I've run around the house looking for my hat that was on my head while running late for work.

Glad you worked it out.
 
Thank you for the results of your investigation. Far too many we solve their problem and never hear from them as to which suggestion solved it. So Thank you big time for that information.
Glad we could help.
 
Got a better one. Looking for my phone when I was talking on it. LOL
My wife once was looking for her phone while using the phones flashlight function on her phone. Another time, she complained that her wireless computer mouse wasn't working. Turned out she was trying to use the cable tv remote as the mouse. She was really tired, working on her masters degree after working 12 hour shifts three days straight in a busy ER.
 
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