Hi everyone. I have a confusing situation with my holding tanks. I have a 2018 3921GK with two gray tanks and one black tank. Originally I thought my InCommand system was not working properly for gray holding tank 1 because it never showed and gray water in the tank. I figured it wasn’t reading the sensor. Meanwhile I was noticing that the gray holding tank 2 was filling awfully fast and I was dumping it ever other day. I just purchased a new sewer hose with a clear elbow and decided to investigate the problem. I ran a constant flow of water into my kitchen sink and went and opened the gray 1 valve. No water flowed from the tank. It seems that all of my sinks and showers are plumbed into gray tank 2.

I can think of two possible possibility:

1. Someone at the factory made a mistake and plumbed everything into gray tank 2.

2. The system is designed to spill over into gray tank 1 after gray 2 becomes filled.

There are two physical gray tank pulls in my utility cabinet and there are two gray tanks configured in my InCommand System. I have never had water come out of the tank labeled gray tank 1. My coach literature indicates a gray tank capacity of 88 gallons. There is no way I’m holding anywhere near that in my gray 2 tank. Anyone else experiencing this? I guess I might have to end up taking things apart to understand the mystery of gray tank 1????

It sounds confusing for sure...

Not all of the plumbing should go to one tank (from the factory).

Now, there are some individuals who have been connecting both of their tanks together. But from the factory, I have not heard about them doing this...yet...

We have the older 2014 38GK.

The Kitchen, Dishwasher and Shower are connected to one tank (called Galley Tank)

The sink in the bathroom, the sink in the bedroom, and the washer are connected to the other tank (called Grey Tank).

Unless Redwood has connected the two tanks together like so many have done, then I would say that you have a quality control issue. They may be all connected to one tank and the other was never connected to anything.

Sounds like that would be one to return to Redwood (or the dealer) for warranty.

I would propose the following:

1) Close both grey tanks

2) Run all water resources

3) Watch for the water to back up in to the shower. That is the low point that will fill up first for one tank. No harm here.

4) For the other tank, you may just want to run for about 10 minutes. No point overflowing the other tank. That would be enough water to demonstrate water is flowing from that 2nd tank.

5) Then, pull the handle on the 2nd tank that never seems to have anything. If you never get anything out of that tank, they are must not be connected.

When you are in the Utility Closet (where the handles are), on ours, they are arranged from top to bottom:

Black Tank (Goes without saying. It's a field of dreams moment)

Galley Tank (Kitchen sink, dishwasher, shower) - 1st tank

Grey Tank (Bathroom sink, bedroom sink, washer) - 2nd tank

Here are the plumbing diagrams for the 2014 GK. I don't have the one for the 2018...they should be the same??

The early FL's had a similar problem, with only the washer being plumbed into 1 tank and all others into the other tank. Since we don't have a washer/dryer we only had 50% usable capacity.

We and many others installed an additional valve just before the outlet. Ensure the black tank dump valve is open, close the new valve and open both grey tank dump valves. Since both our tanks are at the same level, they fill equally.

Andy,

I think you meant ensure the black tank valve is "closed"

OMG, thanks Terry. Yes, the black tank should be closed.

Well I did call Redwood today and they indicated that my unit is certainly not designed for the tank to flow from one to another. They are two separate gray tanks. The guy I spoke with sounded completely baffled and of course indicated I should take my coach back to the dealership. Uggh!!!! I crawled into my basement access to try and see if the plumbing would give me a hint but since all the tanks seem to be in the underbelly that will have to be pulled to see what they did.

I'm really starting to question my Redwood purchase decision. I realize that all new RV's have their issues but a major plumbing mistake like this raises alarm bells with me. Here are a couple of pics of my InCommand display and my utility cabinet illustrating the two gray tank pulls/valves.

Oriana - I did install a washer/dryer and it too drains into the same gray tank (gray tank 2) that all of the other plumbing fixtures seem to be plumbed into.

Well I did call Redwood today and they indicated that my unit is certainly not designed for the tank to flow from one to another. They are two separate gray tanks. The guy I spoke with sounded completely baffled and of course indicated I should take my coach back to the dealership. Uggh!!!! I crawled into my basement access to try and see if the plumbing would give me a hint but since all the tanks seem to be in the underbelly that will have to be pulled to see what they did.

I'm really starting to question my Redwood purchase decision. I realize that all new RV's have their issues but a major plumbing mistake like this raises alarm bells with me. Here are a couple of pics of my InCommand display and my utility cabinet illustrating the two gray tank pulls/valves.

I feel your pain...

Too many things to list...But if you think any other "Brand" is any better, you need to read posts on other blogs and newsletters. This is an industry problem. Conglomeration is the name of the game. THOR being one of the biggest (Your Redwood).

I've said it more than once, I stand by regulation and oversite. But, it's not going to happen until a consumer watchdog group is able to organize enough people and gather enough funds to buy out politicians. The RVIA has plenty of deep pockets and they protect the industry with everything they have.

If your pockets are deep, there are a couple of custom builders. They take directions from you. Not a trade organization.

Here is one of the better articles I've ever read. It's long but spot on. If this were a movie, I would go see it several times::

Part I: http://rvdailyreport.com/opinion/opinion-the-rv-industry-death-spiral-part-1/

Part II: http://rvdailyreport.com/opinion/rv-death-spiral-manufacturers-in-race-to-the-bottom/

Part III: http://rvdailyreport.com/opinion/rv-death-spiral-suppliers-in-a-tough-spot/

Part IV: http://rvdailyreport.com/opinion/rv-industry-death-spiral-part-4-dealers-drop-the-ball-on-service/

Part V: http://rvdailyreport.com/opinion/rv-industry-death-spiral-part-5-campgrounds-losing-capacity/

Part VI: http://rvdailyreport.com/opinion/rv-industry-death-spiral-part-6-associations-can-influence-change/

Part VII: http://rvdailyreport.com/opinion/rv-industry-death-spiral-part-7-rv-owners-share-the-blame/

Part VIII: http://rvdailyreport.com/opinion/rv-industry-death-spiral-part-8-rv-media-falls-asleep/

GipC thanks for the advice on trying to fill the tank to see if it overflows to the second tank. I haven't tried it yet as I spoke with Redwood today and they said the tanks were supposed to be separate. Also thank you for the plumbing schematic. I have scheduled a time with my dealer in December.

Another interesting article:

RV industry goals ignore consumer interests

http://rvtravel.com/rv-industry-goals-ignore-consumer-interests/

Well I did call Redwood today and they indicated that my unit is certainly not designed for the tank to flow from one to another. They are two separate gray tanks. The guy I spoke with sounded completely baffled and of course indicated I should take my coach back to the dealership. Uggh!!!! I crawled into my basement access to try and see if the plumbing would give me a hint but since all the tanks seem to be in the underbelly that will have to be pulled to see what they did.

I'm really starting to question my Redwood purchase decision. I realize that all new RV's have their issues but a major plumbing mistake like this raises alarm bells with me. Here are a couple of pics of my InCommand display and my utility cabinet illustrating the two gray tank pulls/valves.

I feel your pain...

Too many things to list...But if you think any other "Brand" is any better, you need to read posts on other blogs and newsletters. This is an industry problem. Conglomeration is the name of the game. THOR being one of the biggest (Your Redwood).

I've said it more than once, I stand by regulation and oversite. But, it's not going to happen until a consumer watchdog group is able to organize enough people and gather enough funds to buy out politicians. The RVIA has plenty of deep pockets and they protect the industry with everything they have.

If your pockets are deep, there are a couple of custom builders. They take directions from you. Not a trade organization.

Here is one of the better articles I've ever read. It's long but spot on. If this were a movie, I would go see it several times::

Part I: http://rvdailyreport.com/opinion/opinion-the-rv-industry-death-spiral-part-1/

Part II: http://rvdailyreport.com/opinion/rv-death-spiral-manufacturers-in-race-to-the-bottom/

Part III: http://rvdailyreport.com/opinion/rv-death-spiral-suppliers-in-a-tough-spot/

Part IV: http://rvdailyreport.com/opinion/rv-industry-death-spiral-part-4-dealers-drop-the-ball-on-service/

Thanks GipC - BTW it's not even Thor anymore. Redwood is now under Keystone.

But Thor owns Keystone, along with just about any other brand you could name.
Thor & Forest River are the rv industry.

You may want to read this...Be sitting down...

https://en.wikipedia.org/wiki/Thor_Industries

Look under Corporate Hierarchy:

http://listings.findthecompany.com/l/19299172/Keystone-Rv-Company

THOR Owns all of these:

Recreation vehicles

Airstream
Bison Coach
Breckenridge
CrossRoads RV
Cruiser RV
Dutchmen RV

DRV
Entegra
Heartland RV
Jayco, Inc
Keystone RV
KZ RV
Livin Lite RV
Redwood RV
Thor Motor Coach (combined Four Winds International and Damon Motor Coach)

Ok you guys are making me feel somewhat better. Whatever I bought I'd be having issues! Lol. I might as well deal with it. I was looking at a DRV (owned by Thor also).