Gray water backup.

[rodowd]

I accidentally let my gray water tank fill up on my t-1950 and it backed up into the kitchen sink rather than the shower. Is this normal or is there something wrong with the plumbing? Shouldn't it backup in the shower (which is lower?)Thanks

 

[mainah-SUN]

Some RV showers drain into the black tank maybe some one can tall you about the T1950.

 

[JohnGB]

Yes, "commonly" a full gray tank will come up in the shower basin first.

Since yours came up in the sink first, that is different then the common shower rise.

And there are some floor plans with 2 grays tanks, the T280SR's with a front kitchen have 2 gray tanks due to the floor plan. In this case the shower and the sink are in different gray tanks so a sink back up would be doable.

But on a T1950 and a 2006 model which I think is what you have, that does not fit as I do believe you only have 1 gray tank.

Does your shower drain properly when the gray tank is low enough to accept water? If it does, then it is working OK and we have a new mystery going on with the kitchen sink. If the shower is plugged off some how, then that would explain the kitchen sink.

I have not heard the kitchen sink back up before on a single gray tank setup. Maybe another member has.

John

 

[rodowd]

Thanks John. The shower works fine normally. There is only one gray tank. This mystery is driving me crazy.

 

[Gene-SUN]

Years ago when I got my 2363 I wondered about where the shower drained since, as mainah said, some drain into the black tank. I opened the dump valve for the empty grey tank and put a plastic bucket under the opening. I put some food coloring into a gallon jug and poured it down the shower drain. The colored water ran into the bucket so I knew my shower drain went to the grey tank.

There were a lot of things to "explore" and questions to answer in my "new to me" trailer. :-D

 

[rodowd]

Thanks Gene,
I did what you suggested and the shower does drain into the gray tank. Which makes this even more of a mystery.
I replicated the issue again yesterday. Filled up the gray and it backed up to the top of the shower floor drain and stopped - but as I added more water, the kitchen sink filled up but not the shower. How?
Thanks for your help.

 

[mainah-SUN]

Gray tank vent pipe? Wonder if it maybe blocked? The kitchen and bath drains are about at the same level.

 

[rodowd]

Thanks - but the mystery is that the water backs up into the actual kitchen SINK before the SHOWER drain (which is three feet lower.) The sink will fill up (and stay full) and yet the water never backs up into the shower.

 

[JohnGB]

Thanks - but the mystery is that the water backs up into the actual kitchen SINK before the SHOWER drain (which is three feet lower.) The sink will fill up (and stay full) and yet the water never backs up into the shower.

H'mm.... this sort of defies the laws of physics... OR there is one of those laws we do not yet understand....

Question: Does your camper have a pipe trap on the kitchen sink? Maybe the prior own took it out.

If you are coming up in the kitchen sink that is apprx 3 feet higher then the shower then somehow, the kitchen sink has an easier path of resistance then the water coming up in the pipe trap in the shower.

mainah's point about the vent pipe being clogged over has some merit but your last statement kind of points to something else going on or a combination there of.

Question no. 2...: Does the shower drain, drain real fast (like it is suppose to) or does it trickle drain going down? Basically if you pour 2 qts of water down the shower drain, poof it's gone in less than 2 seconds OR does it sit there and take 20 plus seconds to drain?

Question no 3...Does the kitchen sink drain, drain continuously (like it is suppose to) or does it trickle drain going down? If you run the sink for several minutes on an known partly empty or empty gray tank, does it back up in the sink after 3 to 4 gallons worth? Looking for a partly clogged drain pipe.

If 3 feet is correct (sounds right) it takes 1.3psi to push water up hill 3 feet in a pipe. Water - Pressure and Head

If the shower drain is say, 6 to 8 inches above the top of the tank, it takes approx 0.2 to 0.3psi to push water uphill out into the shower. The shower should win...

This acts like there is a blockage in the shower drain not allowing water up into the shower OR a blockage in the kitchen sink drain pipe somewhere not allowing the sink water to drain down into the gray tank.

Question no 4... How exactly are you creating this test? How are you filling the gray tank? Maybe this will lead to some clue on what is going on. How long has this problem existed?

Question no 5... What is the bath room sink doing? Is that drain higher or lower then the kitchen sink and does water drain 3 plus gallons just fine?

I must admit, this is the first time on SOC this topic has come up I recall. This one has my curiosity up big time...

 

[krazedave]

The same thing happened to me 2 years ago while camp hosting in a Pa park. When I went to work I asked the owner of where I work about it. He said he had seen it before. They sold Sunlines for 10 years and called Sunline about it and could not come up with an answer of how it happens. I have a 06 264SR.

 

[Gene-SUN]

..... This one has my curiosity up big time...

You ain't the only one.

And now krazedave said it has happened to him.

 

[JohnGB]

The same thing happened to me 2 years ago while camp hosting in a Pa park. When I went to work I asked the owner of where I work about it. He said he had seen it before. They sold Sunlines for 10 years and called Sunline about it and could not come up with an answer of how it happens. I have a 06 264SR.

Hi Dave,

This is getting even more odd now...

While both RODowd and you have 2006 models, I do not think that is part of the equation as the 10 years comment does not fit.

I am not fluent in the T1950 on exactly how the piping is setup (been in them, just not in depth on the piping), but I happen to have access to a 2006 T264SR real close I can go look at.

On your backup, did it come up in the kitchen sink or the bath sink before the shower? Neither one of them add up right now, but the piping is different between the two. Maybe that will shed some clue on this.

There is obviously a pressure difference and the lowest pressure drop is winning to were the water will come up at. I have a wild thought on how that pressure difference may be occurring, just need to confirm it is your kitchen sink or the bath sink before start doing a bunch of cal'u'latin.

This one ranks up there with the squirrels eating the rubber LP lines... Never knew that could happen before until learning it right here on SOC!

Thanks

John

 

[krazedave]

Hi John, When I saw the water in the kitchen sink I went right to the bathroom and checked the shower and sink and no water backup. Dave

 

[mainah-SUN]

Thanks - but the mystery is that the water backs up into the actual kitchen SINK before the SHOWER drain (which is three feet lower.) The sink will fill up (and stay full) and yet the water never backs up into the shower.

There is a device that lets air into the drains it is designed to allow air into the drains when you open the dump valve so that it does not suck the water out of the "J" trap. I don't know what would happen if it does not open during normal draining. If you look at the drain system there is a plastic device that is higher than the drain pipe it is screwed into the connection usually not so tight that you can't remove it by hand. see if you can get it off then try the drain and see what happens. It will either have to be put back on or replaced if that fixes the drain because it is meant to be closed when the drains are not being use to keep the tank smells from getting into the camper.

 

[ROC-REQS]

Some food for thought.

Could it have anything to do with design of the p-traps or how the shower & kitchen sink drain into the gray tank.

For example, if the kitchen sink drain's straight into the gray tank but the shower drain has a horizontal incline run before dropping into the gray tank.

Honestly, I can't see how this would make a difference, but I thought I would through it out there.

This thread is definitely and interesting topic to following.
I'm very interested to see what the outcome is.

Good luck.

 

[mainah-SUN]

Drain the gray tank leave the valve open turn on the shower if it comes out the open drain then for sure it drains into the gray tank.