[Richard]

This subject has been addressed twice this year, but buried in otherwise titled posts. My purpose is to make a appropriately titled post for future gurus who could use the search engine to find the information. 

Here is a schematic of how the two valves are plumbed to the waste tank. 
   

The first thing to understand is that the grey water does not flow directly into the top of the waste tank. All grey water is plumbed into separate lines that eventually connect and flow into the waste tank through the bottom dump opening in the tank. Look at the diagram and you see how that happens. Compare the diagram to what you see in your wet bay. 

In normal operation, the manual valve is left open, and the air valve is closed. The grey water flows into the waste tank in this configuration. To dump the tank, the air valve is actuated. 

However, there is an alternative setup. Close the manual valve. Open the air actuated valve. In this configuration, black waste will accumulate in the tank, and grey water will continuously flow out the sewer drain. To dump the black tank requires opening the manual valve. 

I hope this helps in understanding a non intuitive setup.

[encantotom]

i have walked through this with many of the gurus as well.

each of us have our ways of managing our waste tank.

i will give you how i do it.

we lived in our coach for 7 months last year while on our mission.

i have an external water softener that needs to be recharged after 4 water tank fills.

so how i like to do it is this.

1. i dont hook up permanently to water.
2. i leave both waste tank valves closed.
3. i monitor the water. when the water is almost gone, i know the waste tank is almost full.
4. i open the manual valve, then the air valve and with a full tank i know i am getting a powerful flow to get all the goodies out of the waste tank. then i close both valves once empty.
5. i leave the waste tank sewer hose on.
6. i fill the water tank through the water softener. i keep track of how many times i use it and then recharge after 4 fills.

4 fills was calculated by know the grains of hardness of the water where i was at and the capacity of the softener. ymmv

then i put the softener away to keep it out of the sun

that is how i do it. but other ways to do it for sure

tom

[RussWhite]

With the exception of not having a softener, I manage my tanks exactly as Tom does. Never had a problem in countless cycles.

Russ

[bestgenman]

I found it difficult to operate the manual valve so , I changed it to air operated, added a spool valve and a spdt center off momentary switch.   I prefer dumping on the curb side and using the connection for water in order to flush the tank.

2 cents!

[rundlc]

   

I think this is my air assist valve, I have not seen this operate yet. To be honest I'm not sure if it works at all. I found a waste master remote control but after putting in a new battery it didn't seem to operate anything. So if this valve opens I can use as the gray water bypass?

I noticed at the very top there is a "u" shaoed pipe in line but it seems weird to me. Sorry for being such a dunce but I'm not grabbing this idea. I was thinking that the air assist helped the drain pipe to extend and retract. This happens when you purchase a used rig and the p.o. is not able to explain how things work.

[Richard]

The plumbing setup I described is on the other side of the coach, in the water bay.

Your picture is in the Aquahot bay if I see the overflow tank for the AH. Where does the black pipe coming out that “thing” go? The wired device is indeed an electrically operated gate valve. What all that does is not clear to me.

[rundlc]

Richard,

Yes in ah bay. That drain pipe appears to be coming from either the sink or d/w It is a mystery to me so far. I put in an email to the guys at newell in hopes of having some light shed on this setup. it looks like gray water could flow down and into the main drain because it enters the discharge pipe after the gate valve. there are two gate valves on the curb side, one wraps around to the driver side like normal and the other is directed to the curb side and then the mystery gate valve in the pic.

[Jndroark]

Rundlc

Our sewer valves are located on the curb side in the AH bay. The sewer master waste hose is connected to the waste dump valve and runs through or under the waste tank to the drivers side of the coach. There is also an air actuated valve, located in the AH bay, that retracts the sewer master waste hose back into the wet bay on the drivers side of the coach.

As a side note, I was told the the inventor of this system failed to patent it. Prevost now owns the patent for the system that retracts the sewer hose and Newell no longer can get parts for the system, not sure if the is correct or not.

[rundlc]

Jndroark,

Thanks for the help, so that valve does nothing except extend and retract the hose. Is it supposed to be automatic? What makes it operate? Whenever I pull the hose it just starts to pulls right on out.

Again thanks to all!

[Richard]

The electrically operated valve simply opens and closes the flow in that pipe. No way that valve automatically retracts anything