2009 Supernova rmaster bathroom sink not hooked up to Grey, but hooked up to black !

[Christyttoon73]

Hi everybody,

So we purchased a 2009 Supernova 6400 back last Nov, only 40000 miles on her. We replaced/ fixed a few things but overall she is in great shape. Will be replacing roof this fall since a couple leaks have popped up after a lot of travel this summer.

BUT we discovered after our 3 week trip to Montana that the master bathroom sink drains in the rear black tank, NOT the Grey tank. The shower drains into Grey tank, though. Had to have been that way since factory I would think and never corrected. My question is, has anyone run across this issue , and if so, how hard of a fix was it. Ridiculous that the problem exists, but I want to get it fixed so I am not filling up my black more often than I should be. We boondocks a lot when on long trips and it was driving us nuts since we filled up that black tank so fast. And thought we had a clog in the Grey for the longest time��.

Any help/ suggestions/input would be great!!

 

[Chuck v]

This is common to have the bath sink going to the black tank. More black tank issues are due to too little water being used with the waste than any other issue or cause. It does not need to be "fixed" or changed. My 2007 Tour Master diesel pusher coach also had the bath sink going to the black tank...this is a feature and not an error.


Note this statement from another RV website:
The RVIA standards only allow one sink to drain into the black tank. Most commonly that will be a bathroom sink due to the plumbing, tank layout, and tank capacity. The bathtub is never allowed to drain into the black tank due to the obvious backup hazard.


Chuck

 

[THenne1713]

Just need to conserve water vs running when washing hands, esp. if boondocking; YES, very common. Warn all adults, Supervise all kids.

 

[Dennis4809]

I think the majority of people have the opposite problem, ie, the gray filling much faster than the black. Having the bath sink on the black tank allows for some flexibility. If gray fills to fast, use the bath sink more. If black capacity is the problem, use the kitchen sink more.

 

[unom]

If your black and grey share a common “exit” from the rv into the sewer dump hose, you can equalize your tanks while boondocking. Grab an extra valve:
Valterra T58 Twist-On Waste Valve https://www.amazon.ca/dp/B000BGHYJS/ref=cm_sw_r_cp_api_glt_i_08FE8WD814635QZ8JK9P?_encoding=UTF8&psc=1

and install it where your sewer hose would connect. Make sure it’s closed, then open your black and grey valves. Whichever tank is fullest will flow into the other tank until they are equal in volume. So instead of being limited by your 30gal black, or your 30 gal grey, you are now limited by your 60gal everything tank.
Some people find it disgusting to think of black water in the grey tank, but as far as I’m concerned, they are both pretty foul.

I would keep the black and grey valves closed except for while you are equalizing the tanks. When it’s time to dump, open your new third valve, then dump as normal.

 

[jamesham]

Lack of enough water in the black tank would be a more serious problem. Having the bathroom sink drain into the black tank is very common. The shower or bathtub draining into the black tank is a more serious problem because of the overflow backup danger. I have had the tank fill and backup while taking a shower and it is NOT a pleasant experience. Finding room to change plumbing may be impossible. An alternate is to install a third gate valve to allow flow between the two tanks to equalize the load if you find the black tank is filling much too quickly.

Hi everybody,
BUT we discovered after our 3 week trip to Montana that the master bathroom sink drains in the rear black tank, NOT the Grey tank. The shower drains into Grey tank, though.

 

[Sundancer268]

My 75 Taurus TT and my 95 Gulf Stream Scenic Cruiser were plumbed to the Black Tank, only my 84 Shasta was plumbed to the Gray tank, This is not an issue