Gray water mixing with black

[Cooter-THOR]

Prepping for first trip of the season and checking for leaks. When I added water to the gray water tank, it would not flush out as normal. It would only flush out when I opened the black water valve. Has anyone ever experienced this?

 

[Jimbo57]

How are you adding water to gray tank , through the sink, shower.

 

[PS89]

Let me guess, you were running water down the bathroom lavatory drain. That empties into the black tank.

 

[Cooter-THOR]

I was using the bathroom sink. I do believe you nailed it.
Thanks

 

[Cooter-THOR]

I just added water via the kitchen sink only and you were absolutely right. Thanks to all of you for your assistance.

 

[16ACE27]

I just added water via the kitchen sink only and you were absolutely right. Thanks to all of you for your assistance.

Now you know. Mystery solved - conditions normal.

 

[PS89]

FWIW, download the plumbing schematics for your particular coach, whatever it is, directly from your Thor owner's account. All this stuff is laid out in the diagrams.

 

[Sagardner290]

Just out of curiosity, why is the bathroom sink connected to the black tank? I just verified with my schematic that is how it’s set up.

 

[Jimbo57]

It helps with extra water in black where as shower and kitchen sink handle more water

 

[Sagardner290]

Makes sense. Thanks!

 

[PS89]

It helps with extra water in black where as shower and kitchen sink handle more water

And on that note, we started holding the shower sprayer into the bathroom sink while waiting for hot water before our showers. Helps keep the gray tank from filling up quite as quickly as it's prone to doing from showering and dishes. Not worth installing a Water Miser for our usage patterns.

 

[rudyhehn]

My Palazzo bathroom sink also empties into the black tank.

 

[Chateau_Nomad]

Many motorhomes are plumbed this way, including mine. I'll be blunt... this ranks up there as one of the STUPIDEST ideas. Seriously?? Why not just EDUCATE buyers by informing them of the importance of adding water to the black tank... easily accomplished by FLUSHING water into the empty black tank.

IMO, this is either a cost saving move... OR an insult to the intelligence of customers. Please tell me it's cost savings??

 

[16ACE27]

How about simply - easier to plumb?

The toilet is usually between the shower and sink. The toilet drops "straight" into the black tank and the shower dumps pretty close straight into the grey tank. The sink would have to go around the black tank to get to the grey tank. The black tank is closer and easier in most cases. Of course there are exceptions to this layout.

 

[Chateau_Nomad]

How about simply - easier to plumb?

The toilet is usually between the shower and sink. The toilet drops "straight" into the black tank and the shower dumps pretty close straight into the grey tank. The sink would have to go around the black tank to get to the grey tank. The black tank is closer and easier in most cases. Of course there are exceptions to this layout.

All mine needed was a Y into the kitchen sink plumbing. They basically made our bathroom sink useless when boondocking. A minor annoyance we've adapted to.

 

[PS89]

Between showering and dish washing, we use far more water that goes into the gray tank than will go into the black tank from the toilet or lavatory. One 50 gallon fresh tank, two 40 gallon waste tanks.

I'm fine with the lav draining into the black tank. I view it as helping to balance the waste load between the two tanks.