Gray Water Tank Question

[jdr0752]

I am an RV newbie and recently purchased a 2019 White Hawk MRB. If this topic has already been discussed in this forum, please forgive me for posting this again here.

Hooked my water up to a city water connection for the first time. The connection made is correct on the RV where it says "City Water Connection", and I have a water pressure regulator attached at the water spigot.

Checked for leaks...none...turned on cold water faucets to allow for air pockets to escape. Water comes thru all faucets...no problem.

After a short time, I noticed water rising in the kitchen sink. Ran and shut water off. Opened the Gray Water tank valve, and water came gushing out of the tank that was previously dry and empty.

Does anyone here have any suggestions as to what might cause the gray tank to fill when connected to city water?

Thank you!!

[Jim Davis]

The first thing that comes to mind is that the tank wasn't drained in the beginning.

[jdr0752]

Originally Posted by Jim Davis

The first thing that comes to mind is that the tank wasn't drained in the beginning.

Thank you for your reply.

The grey water tank was completely empty before the city water was connected. So that does not appear to be the problem.

[Grumpy]

There is no physical connection between the grey water tank and the freshwater lines unless the previous owner changed something.

Only other thing is a faucet was left on accidentally.

[jdr0752]

We bought the RV 3 weeks ago from a a Camping World dealer. I emptied both the grey water and black water holding tanks when I got home. There was barely a trickle that came out from both. The RV has sat idle (no water hookup) until today when I hooked up the water from our house spigot to the city water connection. Thus no water has been on and there’s been no leaking faucet.

Camping World said it might be the check valve at the water pump. I don’t know.

Maybe the previous owner did do something, but I would think that Camping World would have checked the functionality of the water system before posting it for sale.

[SuckyFisherman]

Im no professional, but i have a few trouble shooting questions

Did you get water in your bath tub first, this normally would fill before the sink.

Although you say water came gushing out of the grey tank was it 40 gallons gushing because 10 gallons would probably come out at the same speed.

Maybe it wasn't actually full and you need to trouble shoot the kitchen sink.

Try doing it again and pay closer attention to what is flowing. recreating the problem usually helps me narrow things down.

Let us know what you figure out

[Grumpy]

Originally Posted by jdr0752

Camping World said it might be the check valve at the water pump. I don’t know.

That would fill your fresh water tank, not the grey tank. And again no connection between that and the sink.

[LuckyDuck]

Originally Posted by jdr0752

We bought the RV 3 weeks ago from a a Camping World dealer. I emptied both the grey water and black water holding tanks when I got home. There was barely a trickle that came out from both. The RV has sat idle (no water hookup) until today when I hooked up the water from our house spigot to the city water connection. Thus no water has been on and there’s been no leaking faucet.

Camping World said it might be the check valve at the water pump. I don’t know.

Maybe the previous owner did do something, but I would think that Camping World would have checked the functionality of the water system before posting it for sale.

If the check valve in the water pump was bad, you’d see the freshwater tank fill/overflow, not the gray. I don’t know of any direct connection from the pump or distribution lines to the gray tank.

Here’s a long shot: When you dumped the gray tank initially, did anything come out? If not, is it possible the blade valve was stuck closed and you assumed the tank was empty? If so, it could then fill up and if the valve starting working it would allow you to dump it normally, as occurred.

Other than that, dunno. But it may mean digging into the lines to see what might have been modified.

[Shroomer]

Here's another long shot.
Maybe the hose connection was mismarked and you were actually filling the black tank. If both blade valves were open the water would also go into the grey tank and show up at the sink.

[dxrobertson]

Odd the kitchen sink would be the 1st to backfill from a full grey tank; usually the bath shower fills 1st as stated by @SuckyFisherman. Do you have another grey tank?

[dxrobertson]

Or just a blockage somewhere in the kitchen sink drain?

[Shroomer]

My shower has this funky trap which is low profile and fits under the shower pan. It is essentially a soft one way sleeve that only allows water to drain one way. When my Grey tank is full it shows up in the sink. Check to see what kind of trap is under your shower.

[NBHab]

Drain your gray completely, run your water again just for a minute or two and see if any water shows up in the grey. I suspect the sink was plugged.

[jdr0752]

Through out this whole ordeal with the Grey Water Tank being filled when attached to City Water, and being a new RV owner I failed to take into consideration the outdoor kitchen. It is there that I found both the hot and cold water faucets were open, thus all the water coming in via the City Water Connection was going straight through these faucets and filling up the Grey Water Tank. Closed those faucets and all is good.

Thanks to those of you offering advice and suggestions. These were greatly appreciated!

[NBHab]

Good you figured it out. Usually some weird thing we don't think of.

[norty1]

The outside shower is also another place to look! Glad you figured it out!

[TCNashville]

Well at least you know now that none of your drains leak since they were full of water. Glad you got it figured out.

[skids]

Originally Posted by norty1

The outside shower is also another place to look! Glad you figured it out!

but there is no path to the grey tank.

[LuckyDuck]

Originally Posted by skids

but there is no path to the grey tank.

No, but it’s a bit of a surprise to turn on the city-connect and hear water spraying inside the outside shower compartment! In my case, I’d opened the faucets to drain the lines and never closed them.

Glad the OP figured his issue out!

[Roosevelt008]

We bought our old 264BH new and it had pvc debris stuck in the gray water gate valve. It would only trickle when we tried to drain it. Took it into dealer and they dug plastic pieces out and never had a problem with it after that. Perhaps there is some debris in the gate valve area??