BLack tank gray tank issue

[walljoy]

We just finished our first trip in our first RV. Had a great time with only minor issues. When we broke camp I emptied the black tank. Then I closed the black valve and tried to empty the gray tank. There was not much in the gray and I could not get it to empty. I then reopened the black valve and the gray Val ave and the gray emptied. What was I doing wrong? This was not how I thought it was to work. Any thoughts? You all were a great help. Many thanks!

[Country Campers]

Not sure how to help here.
Do you have 2 grey tanks and 1 black tank?
Are you sure you opened the right valves?

Maybe the valves are labeled wrong. If you have 2 grey tanks run water into the sink and then check which one drains it out then mark for sink. Do the same for shower.

If you have only 1 grey tank the grey and black maybe mislabeled.

Just some thoughts.


Brian

[howson]

Your post reads like you were doing the dump in the correct order. I have three separate grey tanks in my 315RLTS and each will independently empty when I open their respective valve. The black is closed when I dump the greys.

I suspect the grey valve didn't quite open correctly the first time you tried it. Opening the black (at least theoretically) shouldn't have any effect.

[Mark_303RLS]

You may have had some solids from the black tank get jammed in the common wast tube. This might initially prevent the grey tanks from emptying. The action of opening both the black and grey tanks might have coincided with how long it took the grey water to push the solids out. A clear fitting between the wast tube and the flex tube to the dump might give you a better idea what going on.

[backtrack2015]

Hopefully Mark has it right above. I'll second the suggestion for a clear fitting as a diagnostic tool. I find it valuable and we only use the toilet for # 1.

[Buckskin]

The best thing I did was install extra sewer cut off valve; got idea from this forum. After installing extra cut off valve I drilled 1/16 inch small hole at top where it connects to camper valve for one grey tank and one black tank; then put very small screw into hole. This locks extra cutoff valve in place to camper and will keep it from coming off and if you every have problem with extra valve just remove screw and replace valve.

Works great for me to prevent black water accidents; lots of great ideas on this forum.

https://www.amazon.com/Valterra-T58-...rv+sewer+valve

[wudwork]

If you don't see whats going thru drain, you might think you were dumping grey when in fact it was black. Get on of THESE and you will know for sure. If all your handles are same color, think about a tie-wrap or something to distinguish black tank.

We just finished our first trip in our first RV. Had a great time with only minor issues. When we broke camp I emptied the black tank. Then I closed the black valve and tried to empty the gray tank. There was not much in the gray and I could not get it to empty. I then reopened the black valve and the gray Val ave and the gray emptied. What was I doing wrong? This was not how I thought it was to work. Any thoughts? You all were a great help. Many thanks!

[Steven@147]

Yup the clear dump elbow lets you know how things are flowing. This thread reminded me to put some lubricant on the dump valve pull handles. Got some in the storage compartment, need to lube them the next time we dump.

[mhankerd]

Steven@147,
What lubricant do you use on the pull valve handles?

[Cate&Rob]

We just finished our first trip in our first RV. Had a great time with only minor issues. When we broke camp I emptied the black tank. Then I closed the black valve and tried to empty the gray tank. There was not much in the gray and I could not get it to empty. I then reopened the black valve and the gray Val ave and the gray emptied. What was I doing wrong? This was not how I thought it was to work. Any thoughts? You all were a great help. Many thanks!

Wally & Joyce - I don't know the plumbing configuration of your Imagine, but sometimes the gray tank drain is a 2" gate valve whereas the black tank is always a 4" gate valve. Our kitchen gray tank is a 2" gate from the far side of the trailer dumping into a nearly horizontal 4" pipe, so always drains very slowly compared to the black or 4" shower gray. You can tell which size gate valves you have by how far the pull handle moves.

Rob