5th wheel Montana--Shower drains into black water tank-- Why

[Max Hubrich]

My neighbors shower drain is piped into the black water tank in his 35' Montana 5th wheel (We are in coastal Maine for 6 months). Why is that done and is there a solution to run it into the gray water tank?

It seems to me that this is not desirable ---

They bought it used and didn't know that fact. The black water tank backs up into the shower floor real soon during normal usage. Not a pretty sight.

[Ray,IN]

I've never heard of a shower plumbed into the black tank. Some years ago RV manufacturers used to plumb the lavatory (bathroom sink) into the black tank because they received many complaints of plugged tanks. The root cause was insufficient water in the tank.
I suggest re-plumbing to route the shower into the gray tank. Just remember to use sufficient flushing water to keep all solids covered in the black tank.This may be accomplished by adding 5G of water immediately after dumping the black tank, which should keep any solids submerged if a partial bowl of water is used when flushing.

[Frankenstien]

Is he sure thats where its going?.... Most of the Montana's of that Vintage have 3 tanks.. 1 gray, 1 black, 1 galley. When I purchased mine (used) I had found that someone had switched the labels for my Gray and black water tanks. The black tank only has the one 4inch intake, direct from the toilet, as well as the 1.75 for the vent. the Gray has one 4 inch with several Ts' (Tub and bathroom sink). The galley is a 2inch.

[FiverBob]

One of my motorhomes had three tanks. The shower had its own tank, but it output was connected to the same discharge pipe as the black tank, but after the black valve. So, I had three handles to mess with to empty the three tanks. I was quite confused the first time I emptied the "two" tanks, and two days later the shower would not drain, yet the tanks showed almost empty. After crawling around a bit I found the third handle displaced from the other two and traced it back to another tank.

Could we have a similar situation here?

Bob

[grampachet]

I think it probably has three tanks, two grey and one black. My 08 Montana does. The galley tank valve is located near the back of the unit, some between the axels which some folks fail to find at first. Have him check the Montana Owners forum, you will find the answer there.

[Max Hubrich]

Thanks for your inputs---

Tony has your answers. I'll let you know what he finds. I also think he has a crack/leak in a/the gray tank(s).

Max