water leak from underbelly [need help]

[elranas]

Grand Design 23BHE new 2021 unit. The first 2 times camping went well. On the last time, while emptying the grey tank (the one under the sink) my wife was using water simultaneously (water pump running) and I noticed a water leak from the underbelly. I actually had to open the protective wrap to help the water out. Any idea what is going on?

[TucsonJim]

Grand Design 23BHE new 2021 unit. The first 2 times camping went well. On the last time, while emptying the grey tank (the one under the sink) my wife was using water simultaneously (water pump running) and I noticed a water leak from the underbelly. I actually had to open the protective wrap to help the water out. Any idea what is going on?

Well, that's disappointing to say the least. Unfortunately, it's going to require trying to repeat the issue and inspecting for the source of the leak. This will mean dropping part of the underbelly to inspect. It would be something I'd try to trouble-shoot myself, but since it's a brand new unit, this would be a warranty issue that your dealer would be responsible to fix.

Jim

[Second Chance]

See my response to your other post...

Rob

[mpking]

I had a similar issue with my used 2017 unit.

First, I'd recommend warranty service. The dealer should fix this.

For me, mine issue ended up being the shower P trap. Either the trap or the line to the gray tank was cracked. (I'm not sure which, I had the dealer fix it as a condition of the used camper sale.)

Jim is correct that diagnosing it will required dropping the bottom.

[elranas]

When the drop the buttom, do the replace it all or patch it?

[elranas]

Okay, so I dropped part of the underbelly (this tihng rips so easy!) and I can see water evedance but no leak. I filled up the fresh, turn ON the water pump and open the kitchen faucet to let the grey fill up. I did that with 36 gallons of water out of the ~40 avaliable in this tank. No leak! I'm not even sure where is the water pump to inspect it but everything seem dry for now. Not sure what else to check...

[howson]

Grand Design 23BHE new 2021 unit. The first 2 times camping went well. On the last time, while emptying the grey tank (the one under the sink) my wife was using water simultaneously (water pump running) and I noticed a water leak from the underbelly. I actually had to open the protective wrap to help the water out. Any idea what is going on?

Your trailer has a feature I think is unique on Grand Design trailers: a sump pump under the kitchen sink. I'd follow the pipe path from sink, to sump, to gray tank to find the issue.

There's also a "side vented system" on the kitchen gray tank. I'm not familiar with a "side vent" -- it's different so it caught my attention. I wonder what would happen if the gray was overfilled--could the water go out the "side vent"? Where does that vent lead to?

I could be wildly and completely off-base, so take my input with a big 'ol dose of skepticism.

Fellow moderators -- please take a look at the DWV Plan. Any thoughts?

Cate&Rob
Country Campers
TucsonJim

[ShaneGreen17]

We had a leak in our kitchen plumbing that was simply the P-trap was not completely screwed on. It actually happened from putting our dish drying rank back under the sink and each time it would hit the tightening tabs and incrementally loosened it. I would run the water and start from the top to see if something similar happened.

[elranas]

Your trailer has a feature I think is unique on Grand Design trailers: a sump pump under the kitchen sink. I'd follow the pipe path from sink, to sump, to gray tank to find the issue.

There's also a "side vented system" on the kitchen gray tank. I'm not familiar with a "side vent" -- it's different so it caught my attention. I wonder what would happen if the gray was overfilled--could the water go out the "side vent"? Where does that vent lead to?

I could be wildly and completely off-base, so take my input with a big 'ol dose of skepticism.

Fellow moderators -- please take a look at the DWV Plan. Any thoughts?

Cate&Rob
Country Campers
TucsonJim

Yes, we do have a sump pump to push the kitchen sink water out to the gray tank since this section of the RV is on a slideout. I followed the drain line from the top to the dump valve including the sump pump and couldn't find any leak. Tomorrow, I'm going to fill the gray tank completely until water fills the sink and then inspect eveything again. I have a suspecion that there is a crack or a hole up higher in the tank/plumbing that is not visual from the buttom of the trailer taking the limited access I have.

You are right about the side vent. I think it is higher than the countertop so water cannot overflow from this pipe, but that was an interesting thought and I will double check what I'm saying tomorrow.

I started working on this today at 1pm and called it a day at 8pm. My fear is that if and when I take it to the dealership they won't be able to replicate the issue so I'm doing everyhting I can to find the leak myself. If it happened once, it will happen again and I would hate to seal the underbelly just to later open it again in the next few trips we do.

Thoughts?

Thank you in advance!

[Cate&Rob]

elranas

With a sump pump in the system, I don’t think that filling until the sink backs up would be wise. Agreed that this is OK in a normal drain system, but the cover on the sump is quite possibly not liquid tight. This is because air has to exit the sump container as it fills with water from the sink and enter as the pump transfer the liquid to the grey tank. Is the cover of the sump the possible location of the “leak”.

Rob

[elranas]

elranas

With a sump pump in the system, I don’t think that filling until the sink backs up would be wise. Agreed that this is OK in a normal drain system, but the cover on the sump is quite possibly not liquid tight. This is because air has to exit the sump container as it fills with water from the sink and enter as the pump transfer the liquid to the grey tank. Is the cover of the sump the possible location of the “leak”.

Rob

No water evedance whatsoever under the sink and around the sump pump. I understand what you are saying about the seal and I will proceed with the test bypassing the pump.

[elranas]

Thanks everyone!
Update and a question: after much effrot I still could not replicate the issue. No water leak whatsoever and the only thing I can think about is that city water was connected while I tunred on the water pump. Could that cause water to leak to the uderbelly from a crack (due to high presure...but I have presure regulator) or some sort of overflow protection?