My bathroom sink drains into the black tank?

[CavalierBob]

We were out a couple of weekends ago in our new (as in first ever) TT, a Rockwood 2715VS Ultra-V. This model has a front bath in the v-nose with two sinks. Two grey tanks on this model, one up front and one midway for the galley.

I thought we had plenty of room in the black tank according to the sensor but noticed that the waste was very far up the pipe for the toilet. The front grey tank didn't have much in it, so I thought I'd run some additional water to help flush the slinky better. I started adding water to both sinks and set back with a beer to watch the front grey tank sensor.

My wife happened to go into the bathroom and called out that one sink was plugged up. Sure enough, the sink closest to the toilet was backing up. Then to my horror, I realized the water was brown. I drained the black tank and, sure enough, the "plugged" sink drained. I disinfected the sink after it was empty.

I talked to my neighbor in the site next to me about this. Mark has been camping for 30+ years. He and Betty Jean were in a Rockwood 5er. Mark didn't think it wasn't right that a sink drained into the black tank.

After getting back home I did a Google search and discovered its not unheard of for grey water and black water to drain into one tank. Apparently pretty normal on boats and on some RV's.

My question is does it seem weird that Forest River would add two grey tanks, 37 gallons each, and then route one sink into the 37 gallon black tank? I kinda assumed that ALL the grey water would route into the grey tanks given I have two of them.

I realize Forest River could save the cost of the PVC to route the sink furthest away from the front grey tank into the closer black tank, but it just strikes me as odd.

Just looking for the groups thoughts and experiences before I place a call to Forest River customer service.

Thanks!

Bob

[VinceU]

Perfectly normal, I've had it when piping routing dictates it and it also extends gray tank time between dumps. Just maintain the trap in good order!

[CavalierBob]

Originally Posted by VinceU

<snip> Just maintain the trap in good order!</snip>

Thanks for the quick reply Vince!

Short of making sure I keep water in the trap to prevent odors from the black tank, anything else you'd recommend I do?

Thanks again!

Bob

[VinceU]

The only other thing comes to mind is use a tank "wand" available at CW or Walmart regularly to keep the tank gage probes clean and you can trust the reading. Very important with occasional use. Happy camping!

[rockfordroo]

I'm wondering how you can get water backing up into the sink, which should be higher than the toilet, without backing up into the toilet first. Seems like something else is also going on.

[prairiecamper]

Our previous trailer was plumbed just that way, bathroom sink grey water was directed to the black tank! Was told by the dealer that the manufacturer designed it that way so when the black tank was being dumped there would be more liquid than normal to make dumping black tank more efficient! I.E. a greater slug of water to move out the solid waste!

[MNtraveler]

Originally Posted by rockfordroo

I'm wondering how you can get water backing up into the sink, which should be higher than the toilet, without backing up into the toilet first. Seems like something else is also going on.

Say the tank is full to the top but not overflowing and the toilet valve is closed and sealed. Then you wash your hands using normal water flow, maybe running the hot until warm water comes out...right? As soon as the P trap spills over the drain fills up and right into the sink.

[CavalierBob]

Originally Posted by rockfordroo

I'm wondering how you can get water backing up into the sink, which should be higher than the toilet, without backing up into the toilet first. Seems like something else is also going on.

My guess was the gate valve on the toilet made a very good seal. Nothing back up into the toilet bowl.

Bob

[rockfordroo]

Originally Posted by MNtraveler

Say the tank is full to the top but not overflowing and the toilet valve is closed and sealed. Then you wash your hands using normal water flow, maybe running the hot until warm water comes out...right? As soon as the P trap spills over the drain fills up and right into the sink.

I understand that, but highly doubt the water would be turning brown if the water going down the drain is relatively clean. Seems odd that something would come UP from the tank when clean water is going down. Not saying it can't happen, but it seems highly unlikely to me.

Especially when the OP said his wife "happened to go into the bathroom," which sounds like NOTHING was really going on. Maybe the tank warmed up, the water expanded, and forced its way up the drain. That I might believe.

[OldCoot]

I would be looking into the possibility of re-routing the sink to another drain that emptied into a grey tank.

[CavalierBob]

Originally Posted by rockfordroo

<snip>Especially when the OP said his wife "happened to go into the bathroom," which sounds like NOTHING was really going on.</snip>

OP here, sorry, I must not have been as clear as I should have been.

I WAS running water into both bathroom sinks at the time when the one that is hooked to the black tank backed up.

Bob

[Batts-toy]

Originally Posted by CavalierBob

OP here, sorry, I must not have been as clear as I should have been.

I WAS running water into both bathroom sinks at the time when the one that is hooked to the black tank backed up.

Bob

Actually you stated it very clearly, that beer you mentioned must have distracted rockfordroo's thought patterns.

[CavalierBob]

Originally Posted by OldCoot

I would be looking into the possibility of re-routing the sink to another drain that emptied into a grey tank.

Yea, that was my thought as well OC. I don't like the idea of that sink being connected to the black tank. Need to get under the trailer and drop the bottom cover(s) to see what is possible.

Bob

[VinceU]

Originally Posted by CavalierBob

OP here, sorry, I must not have been as clear as I should have been.

I WAS running water into both bathroom sinks at the time when the one that is hooked to the black tank backed up.

Bob

Had you pushed that foot pedal, you'd still be cleaning that space and would have made a believer of all these readers. I've read the same problem before on these forums. Sorta like a bottle rocket ya know?

[Old car]

To confirm if the sink is going to the black tank; can't you start with an empty black tank and start running water into the sink. Open the black tank dump valve and with an old bucket check and see if water comes running out? We have on odor out of our bathroom sink and I have already changed out the trap vent under the sink. Still get the odor so I wonder if I am getting odor from the black tank through the sink. I am going to try checking it my way stated above to see what happens.

[spower]

Oh man I sure hope my 2016 2604ws is not set up that way!! Not a good setup for a boondocker.
Is there a way for me to find out without too much trouble?

Thanks!!

[MOODMAN]

Two things going on here...
1. I don't think it is EVER a good thing to route gray water to a black tank. Besides the potential backups, there is the odor issue. You shouldn't smell stanky frmo any sink.

2. I am wondering if your gauges are accurate. If not (and RV gauges are notoriously unreliable) I recommend the installation of an ultrasonic gauge that goes on the outside of the tanks. They are very accurate, and should give you more peace of mind.
Check this link LevelGuard SensaLevel Ultraâ„¢ Tank Sensor with Field-Effect sensing

[JPSPete20]

Our Salem 27 RKSS, which is really 31 plus feet long has a rear kitchen and forward bath. We have front and rear gray water tanks and one black tank directly under the toilet. The two grays feed the same line which ties to the main dump line.

There are valves on all lines. If one gray tank starts to get too full (kitchen) we can open the two gray valves and the tanks will equalize. This has been useful when dry camping. The only way we could get black into the gray system would be to open the black drain valve and one, or both, gray valves with the cap on the main dump.

If your second front sink does go into gray tank, I would simply reroute the two sink drains together. And as I said, if the two gray tanks are connected you may "equalize" between the front and rear as I described.

[Tom48]

I wonder the way the brown water backed in to the sink if maybe a worker cut a corner and tied the sink to the black tank vent.? Are there two vents running up to the roof together and the factory plumber tied the sink to the wrong one? Just wondering cause mine are all in walls were I can't look at it.

[jeff64]

Originally Posted by CavalierBob

We were out a couple of weekends ago in our new (as in first ever) TT, a Rockwood 2715VS Ultra-V. This model has a front bath in the v-nose with two sinks. Two grey tanks on this model, one up front and one midway for the galley.

I thought we had plenty of room in the black tank according to the sensor but noticed that the waste was very far up the pipe for the toilet. The front grey tank didn't have much in it, so I thought I'd run some additional water to help flush the slinky better. I started adding water to both sinks and set back with a beer to watch the front grey tank sensor.

My wife happened to go into the bathroom and called out that one sink was plugged up. Sure enough, the sink closest to the toilet was backing up. Then to my horror, I realized the water was brown. I drained the black tank and, sure enough, the "plugged" sink drained. I disinfected the sink after it was empty.

I talked to my neighbor in the site next to me about this. Mark has been camping for 30+ years. He and Betty Jean were in a Rockwood 5er. Mark didn't think it wasn't right that a sink drained into the black tank.

After getting back home I did a Google search and discovered its not unheard of for grey water and black water to drain into one tank. Apparently pretty normal on boats and on some RV's.

My question is does it seem weird that Forest River would add two grey tanks, 37 gallons each, and then route one sink into the 37 gallon black tank? I kinda assumed that ALL the grey water would route into the grey tanks given I have two of them.

I realize Forest River could save the cost of the PVC to route the sink furthest away from the front grey tank into the closer black tank, but it just strikes me as odd.

Just looking for the groups thoughts and experiences before I place a call to Forest River customer service.

Thanks!

Bob

I would be very suspect here. I have the same TT you do and I am almost certain that all the grey water from the bath goes into the front, grey tank #1. I know my black tank sensor doesn't read correctly, but that's a different issue