Gray 2 tank overflowing in to underbelly on 315RLTS

[beedlebum]

Took our 2022 315RLTS for first trip out in April. As a newbie, I of course left it too late to empty the tanks and I noticed water coming out of the underbelly. Not a disaster, could have been worse, and I cleaned up the mess, telling myself not to be so stupid again. I was a bit disappointed though, because I had heard from other campers that water should back up in to the kitchen sink if that tank is full to let you know, but I guess this model doesn't do that. So, I started emptying the tanks every couple of days. Even after emptying, the gauges often show 2/4 and 3/4 when empty, but I hear that is quite common. As a precaution (in case I had damaged anything with my flood) I took the RV in to the service center at the dealership to check the plumbing and after 3 hours of testing they said there was no problems with it.

Fast forward to today, I am at a campground with no hookup. The guy who comes round to empty my tanks said that I had a leak coming from the underbelly. My Gray 2 tank holds 43 gallons and this happened after only 3 days. We empty the bowl in the kitchen twice a day, but we are nowhere near using 43 gallons in 3 days.

My problem now is that having just emptied my tank, it still reads 4/4 and when we empty the kitchen sink it floods underneath again. We are fanatical about not letting food down the drain so it can't be a blockage.

Any suggestions would be greatly appreciated.

[huntindog]

Is your kitchen sink in a slideout?

[beedlebum]

Is your kitchen sink in a slideout?

No, it is on a fixed island.

[huntindog]

No, it is on a fixed island.

Could be a number of things. I have read of pipes, entering the top of the tanks not sealing well. But having installed one myself, that grommet setup they us is pretty stout.I can't imagine it leaking. OTOH, never underestimate the factory workers ability to screw something up.
I think the underbelly needs to be dropped, to observe just where that water is coming from. Not a fun job. If you tackle it yourself, where the proper PPE. A full air tight suit, N95 dust mask, or better yet a full face respirator which will protect your eyes as well. That fiberglass insulation is nasty stuff. Any that you breath into your lungs is bad news.
At any rate, continual water leaks in an RV sooner or later brings more trouble, so it has to be addressed.

[wudwork]

Consider empty kitchen sink tank then close the valve. Now use a 1 gallon milk jug filled with water and pour that into sink. Now go outside and dump the kitchen tank into a 5 gallon bucket. Do you get 1 gallon or so out ? as the input into tank is on top, 1 gallon would not rise up enough to test that seal, but the valve would certainly be in play and its above the bottom cover. Try pulling the kitchen tank dump valve a few time and try to see if its sticky or does not feel right. Many RV owners get the Valterra Valve and leave that connected to your exit pipe all the time. I put some black gorilla tape to hold it there. With that valve you can "join" the gray tanks. But that valve won't help here as it would be installed external to bottom cover.
Lowering the bottom cover is not a fun job, but its good to "get in touch" with whats going on down there. As for gauges, the black tank seems to always show too much, but the gray tanks are typically right on. There are other tank gauges you might consider, but the leak is the priority. Keep us posted.

[beedlebum]

Thanks for the advice/suggestions by everyone. I had an "RV repair" guy take a look, and after an hour or so, he reported back that he couldn't find anything wrong. I've been doing a bit more research and I'm pretty sure that this is what I have:
Gray 1 (left pull handle) - Bathroom sink/shower - 43 gallons
Black 1 (center handle) - 43 gallons
Gray 2 (right pull handle) - Kitchen - 32 gallons
Gray 3 ("galley" pull handle in water center in front left storage bay) Washer - 43 gallons (which I'm not using)
After a few rough calculations I think we must just have been overfilling the kitchen tank; will be more careful going forward.
Still a bit disappointed that a) the kitchen tank fills up so quickly (2 days), b) the tank leaks in the underbelly when full rather than gurgles in the sink to let you know, and c) the tank gauges are rubbish! Why don't RV manufacturers use a simple float valve (like in toilet tanks) instead of these useless sensors which get dirty and become inaccurate?

[tjndsa]

We had a similar issue with our island kitchen gray tank. Noticed it within a month of purchasing our RV. Long story short, RV Tech came out and opened up the wall in our basement to get a view of the pipes from the kitchen sink to it's gray tank. The pipe itself was sitting on top of the gray tank next to the outlet opening that it should have been in. Kitchen sink water was emptying out from the pipe all over the top of it's gray tank. Once the top was full, it began filling up our underbelly until it sagged enough for us to notice a problem. All this to say, it might be worth your while to get behind your basement wall to make sure the pipe is actually inserted in the gray tank and not just dumping on top of it.

[beedlebum]

Thanks tjndsa. That sounds terrible, and such shoddy workmanship and quality control by GD.
I'm thinking/hoping that I don't have the same issue as you because we do actually get a lot of gray water coming out when we empty, so I know some water is going in to the tank.
That said, I'm at another campground today with full hookup with both gray tanks left open, and my G2 sensor is on 4/4. I give up!

[kb0zke]

We have the same trailer. We're full-timers, so we are constantly filling and dumping. The panel indicator lights show, from left to right, empty, 1/3, 2/3, full. We don't have a washer, so just the one toilet connected to the black tank, and a kitchen sink, bathroom sink, and shower. Judging from what I can see of the drain pipes, grey 1 is for the bathroom (shower and sink) and grey 2 is for the kitchen sink. The only time the stinky slinky is connected is when I'm dumping.

When the fresh shows 1/3 I fill and dump. When we're traveling we can go another day (no lunch dishes to wash), but usually I dump and fill about every three days. On travel days I'll dump and fill as soon as we arrive at the campground if needed.

[Leatherman]

We were also having an issue with the lights and the tanks not emptying correctly when we first got our 260RD. Low and behold, they wired the panel incorrectly. The black tank was actually wired to the "Grey 1" lights, Black was Grey 1 and Grey 2 (galley) was wired correctly. The pulls to empty were correct.