black flush

[janpaul]

Our new 5er has a black water flush on the outside where you can connect a hose and flush out the tank. When I was winterizing, and checking out all the plumbing lines, I noticed that the line from it comes in beside the fresh water fill and then goes up the wall after coming inside and another line comes out the same hole and goes underneath. There is an enclosed underbelly, so I can't say for sure if it goes to the black tank, or if they are connected inside the wall, but I would almost assume so. Why would this go up the wall when it is to go down to the black tank?

 

[Gary RV_Wizard]

Hard to say and you don't know if the second line is even related to the flush system.  Might be something else routed through a convenient hole.  I would not be surprised if the flusher inlet is at the top of the black tank or high on one side - that could account for it going "up" rather than "down".

 

[janpaul]

It just didn't make any sense because there is nothing above where these lines go up the wall and the black tank, I would assume, is closer to the front where the toilet is. This comes in near the kitchen sink, which is in the rear, and I can see it from underneath the cabinet access. The wall that they go up in is the wall between the main section and the back garage area.

 

[Gary RV_Wizard]

Dunno, I can't explain it either. The line  goes way up, i.e. toward the ceiling? They don't usually run water lines much above floor level, except to actually reach a  faucet, but maybe in yours they chose that route to bring the water to the tank area ifit is indeed up front. Seems like a waste of piping, though, since the black drain line no doubt runs under the coach already. Why not run the flush line right along side of it? A mystery, to be sure.

 

[Ron]

Could it be an anti siphon device ??? ??? ???

 

[Lowell]

Does your 5th wheel have 3 water inlets then?  (1)Fresh water fill, (2) City water hook-up and (3) black water flush?? I was thinking maybe it isn't a black water flush but the city water line if there are only two water inlets.

 

[janpaul]

There are three, the city water is on the other side where the electric plug is and the fresh water fill and black water flush are side by side on the opposite side of the unit. When it warms up and I de-winterize, I will run water in the black flush inlet and watch that other line to see if it flows through there.