Washing Machine Draining to Black Water Holding Tank

[dfredendall]

We recently learned from a new club member that their new Cardinal Model 3875FB equipped with a washer/drier was plumbed from the factory with the drain going to the Black Water Holding Tank. Although as the factory states, "It is not a code violation." It is a major owner inconvenience.
Here is the issue:
Two or less washing machine loads will overflow the Black Water Holding Tank. This requires owners to remember to open the Black Water Tank drain valve during the washing machine use. Even though the Black Water Holding Tank may be rinsed out with the washing machine discharge, the owner needs to remember to close the Black Water Tank drain valve after use of the washing machine.
Failure to close the Black Water Holding Tank drain valve will lead to liquid waste draining through and solid waste remaining inside the tank to dry and solidify within the tank. That condition produces serious odor and clogging problems within the Black Water Holding Tank System. That can lead to expensive repairs to clear/clean the tank if it occurs.

The preferred set up is for the Washing Machine to drain to a gray water holding tank that can be left open without waste consequences. Many 3250 models were plumbed to the Black Water Holding Tank in the past. It is uncertain what other models may have this design. I tested my 2018 3350, and it drains to the bathroom/shower Gray Water Holding Tank. The Factory is not inclined to see it as an issue nor remedy it upon owner request. Some owners have re-plumbed the drain lines on their own accord.

The CAUTION: Since your trailer is equipped with a washing machine that discharges into the trailer plumbing system/holding tank(s) it is recommended that you test the drains to verify which tank your washing machine drains to. You should then operate it with proper drain valve action to avoid serious complications later on.

[djousma]

I had read about this phenomenon on the FR Cardinal forum as well. There is another flavor of this issue too.... I think what you mention and the following scenario it is a mistake on FR part, because the ones that reported it over there indicate that while they have two gray tanks, they indicated that the bathroom sink drains to the galley gray, leaving the other gray totally unused. Not just told that, but actually figured out that nothing goes to that gray tank, as they do not have a washer/dryer. of course, selling dealer indicates that all is working as designed.

I was concerned about this in my 3850RL, but thankfully, is plumbed correctly with washer going to bathroom gray tank.

[Mike Clay]

The 3850s or fine. I have one with a washer and dryer it all goes to the grey tank the dishwasher in the kitchen goes to the kitchen grey tank.

[dpalmer]

On our 3456 the W/D goes to the gally. The shower and bath sinks go to the grey.

[Anton & Sandy Jones]

In our 2015 3875 FB the washing machine drains into the black tank. The shower also drains into the black water tank. Only the sink in the full bath drains into the rear grey water tank. I guess that sends a load of water through that Black water tank.

[Anton & Sandy Jones]

BTW: I did not realize it then , but the sink in the full bath also drains into the Black water tank. Only the shower fills the forward gray water tank. I've learned a lot over the 3 years we have full timed in our Cardinal!

[dfredendall]

The architectural design/floorplan creates this anominally, aka: “feature”. They use shortest path technology. Several models drain the washer to the black tank. Each one has unique characteristics.