Flood

[CoChris]

No washer and dryer But I do have washer dryer hook up

Just a forum tip. When replying to a post if you use the "reply with quote", as I have done here it will copy the original post and notify the owner of that post. This really helps the readability to know who and what your are replying to.

Chris

[Always Learning]

I came back to my trailer to find my shower and bathroom sink overflowing with water. There were no valves on the kitchen sink the bathroom sink or the shower. The water was connected to the trailer and pressurized. How is it possible for my Gray tank to have filled up without water going in ithe great tank directly from Either sink or the shower being turned on?

You have gotten some good comments and suggestions. I am going to throw out some ideas and questions for you to think about.

You said “shower and bathroom sink overflowing with water.” How much water? Cups or gallons?

Was the water flowing out or dribbling out of the sink and shower drain?

How did you get the water to stop coming out of the drains?

If the water was coming out of the sink and shower then there must be pressure behind the water since the sink is higher than the shower.

What happened previous to this flood? Did you add water to any of the grey tanks, did you just hook up the water to the trailer or everything has been inplace for awhile.

The waste tanks in these trailers are vented. On my 2020 337 I have two grey and one black tanks. There is only one vent pipe coming out of my roof so all three tanks have a common vent.

Do you have a venting problem.?

Is it possible that unequal pressures, a vacume, in the common venting system is allowing water to back up in the vent tube until the vacume breaks then the water is forces out the drains in the bathroom. No idea if this is possible but something to think about.

Is this a new trailer? If so this is probable something that would be covered by the warranty but if you can’t reproduce the problem then it would be hard to diagnose. You should talk to your dealer and Grand Design. You never know they might know the problem a fix.

[Jaymee317]

I came back to my trailer to find my shower and bathroom sink overflowing with water. There were no valves on the kitchen sink the bathroom sink or the shower. The water was connected to the trailer and pressurized. How is it possible for my Gray tank to have filled up without water going in ithe great tank directly from Either sink or the shower being turned on?

If the vents of the gray and black tank are connected and you happened to connect to the flush connection for the black tank, instead of the fresh water connection, then you could overfill the black tank into the vent and then overfill the gray tank. I suppose the seal on the toilet is tight enough that this could occur. I am just spit balling now.

Do you know the level of the black tank?

[powerscol]

If the vents of the gray and black tank are connected and you happened to connect to the flush connection for the black tank, instead of the fresh water connection, then you could overfill the black tank into the vent and then overfill the gray tank. I suppose the seal on the toilet is tight enough that this could occur. I am just spit balling now.

Do you know the level of the black tank?

I think you're on to something. If he connected to the black tank flush port instead of the fresh water port and left then the black tank would have back flowed into the vent pipe and then into the rest of the system.

[Dfanelli]

How do you some of your questions there was literally gallons of water flowing out of my bathroom. The flooding stopped when I shut off the city water supply. I didn’t dump the gray tank to illuminate the water that was in the sink and the shower. My gray tank couldn’t even been 10% full as I just set up the day before. I have no venting issues and it’s a 2020 380MI have contacted GD customer service and they are stumped as I am. They claim there is no water source to the gray tank that should be coming from the city. The only thing in the gray tank should be my drains for the bathroom sink and Shower. The dealer however says I have gray tank flush outs which they are full of bull. There’s nothing in my manual about that and grand design them selves by serial number says I do not have that on my trailer. I’m at a loss

[Always Learning]

How do you some of your questions there was literally gallons of water flowing out of my bathroom. The flooding stopped when I shut off the city water supply. I didn’t dump the gray tank to illuminate the water that was in the sink and the shower. My gray tank couldn’t even been 10% full as I just set up the day before. I have no venting issues and it’s a 2020 380MI have contacted GD customer service and they are stumped as I am. They claim there is no water source to the gray tank that should be coming from the city. The only thing in the gray tank should be my drains for the bathroom sink and Shower. The dealer however says I have gray tank flush outs which they are full of bull. There’s nothing in my manual about that and grand design them selves by serial number says I do not have that on my trailer. I’m at a loss

Your trailer is haunted by a gremlin

It sounds like it is time for someone to start taking the trailer apart tracing sewer and water connections until the problem is solved or do nothing and hope it does not happen again. Hopefully it is covered by warranty. If you had that much water running in the bathroom you most likely will have water in your underbelly that needs to be dried out.

If you get this figured out, please post what the problem is.

[powerscol]

How do you some of your questions there was literally gallons of water flowing out of my bathroom. The flooding stopped when I shut off the city water supply. I didn’t dump the gray tank to illuminate the water that was in the sink and the shower. My gray tank couldn’t even been 10% full as I just set up the day before. I have no venting issues and it’s a 2020 380MI have contacted GD customer service and they are stumped as I am. They claim there is no water source to the gray tank that should be coming from the city. The only thing in the gray tank should be my drains for the bathroom sink and Shower. The dealer however says I have gray tank flush outs which they are full of bull. There’s nothing in my manual about that and grand design them selves by serial number says I do not have that on my trailer. I’m at a loss

Can you please do this for us. Pull the wall in your basement pass through and take pictures of the sewer pipping from the sink, toilet, and shower. The sink and shower should not connect to the toilet piping that goes to the black tank. I have a hunch they were incorrectly plumed into the black tank (there have been reports of other models having this issue where the black tank was filling too quickly).

If you mistakenly attached your city water to the black back-flush fitting (city water is the white one to the left of the black fitting) then your black tank would have overfilled pushing water out of the shower and sink. Water would not have gotten to the gray tank as it might not be connected to the sink or shower, and the situation you described would have happened.

Hope this helps

The only way to know for sure would be the plumbing pictures.

On edit - over at the other GD place there are similar layout toy haulers with the pluming issues (black tank filling to quickly). GD is fixing them. Might be worth checking.

I really think you connected your city water to your black tank flush fitting and all the piping is tied together.

[powerscol]

I came back to my trailer to find my shower and bathroom sink overflowing with water. There were no valves on the kitchen sink the bathroom sink or the shower. The water was connected to the trailer and pressurized. How is it possible for my Gray tank to have filled up without water going in ithe great tank directly from Either sink or the shower being turned on?

Any update? Was wondering what you found in the plumbing.
Happy camping