Black water tank flush

Ours has the flusher, with an attachment, to put chlorine tablets in and sanitize the tank as it flushes.
It has a ball valve that leaks. It is plastic. The back flow preventer is nearer the tank. Water still dribbles out from the little plastic quick connect, when you disconnect the flushing attachment or hose. Aggravating but clean water.
Watch the tanks levels as you fill them to flush. A moment's inattention and you will be swelling tanks and bit more you may have water up into the shower or the toilet flange give up.
Our gaauges are in the coach os it is connect the hose go into the coah and watch the level as the black tank fills go out swith to gray tank go in the coah and wait until it shows full.
Go out open the blaacck tank and turn the handle to have clean water enter the tank and stir things around. As the tank empties you will hear it burp.Let it run for fie minutes, the manual says more. Close th valve and put a few gallons like two to five into the black tank.
Turn the fill valve to gray water tank and open that valve. It will take a little longer as it is larger.
After it drains let it fulsh a minute or two close drain valve and let a couple gallons in.
Cut off water, cut the little ball valve off, remove the hose, after turning off spigot, slowly, and unplug the flush gadget.
We use the Rhino hose which takes the considerable pressure of a full tank draining better and it has a opaque elbow end where it connects to the sewer, so you can see when clean water is finally going through.
I have had a couple of the thin sewer hoses burst. Not pleasant and birds etc peck holes or chew holes in them, or step on them with gravel under then and develop leaks and geysers when flushing.
Had one of the red shot extensions, similar to the Rhino material burst in one of the pleats last trip.

Big Katuna wrote:
I have a short hose connected to the flush.

I use the same hose I use for water if dumping at my site.. I let it run a few minutes after disconnecting to flush it.

I recommend getting a short clear extension so you can see what is coming out.

I think it works best to turn on the flusher and open the valve until the flow slows down. Then I shut the valve and let it fill up 4-5 minutes then open the valve again. Repeat several times until no more tp or stuff comes out. I drain the gray in between filling the black saving some for the final rinse.

I was surprised how much stuff comes out after it drains the first time.

I use this process also. Except I do have a long green hose for the flush connected via a Y with dual shutoff at the faucet so I never use my white fresh after hose for the flush. I just leave the green hose connected as long as we are set up so that I can easily do a flush any time I drain the black tank.

There will be an 'anti=siphon vacuum breaker' device in system

Typically installed under bathroom sink cabinet (or possibly in a closet
which when it fails will cause water leaking inside RV :S

Big Katuna wrote:
I have a short hose connected to the flush.

I use the same hose I use for water if dumping at my site.. I let it run a few minutes after disconnecting to flush it.

I recommend getting a short clear extension so you can see what is coming out.

I think it works best to turn on the flusher and open the valve until the flow slows down. Then I shut the valve and let it fill up 4-5 minutes then open the valve again. Repeat several times until no more tp or stuff comes out. I drain the gray in between filling the black saving some for the final rinse.

I was surprised how much stuff comes out after it drains the first time.

Very good advice, that is exactly what I do as well. The clear extension works great, also makes it easier to hook up, you don't have to reach so far under the camper.

Thanks for the info. I figured I had nothing to worry about but wanted to double check just to make sure.

There should be a backflow preventer in the line to the flusher. It may be built in to the flusher, or installed in the line. If it is factory installed, there should be one. your water line should also have a vacuum breaker at the faucet. Most campgrounds have them installed on the faucet. I have a splitter valve on the intake side of my water hose that attached to the campground faucet, and I just use that to connect to the flusher( with bfp installed).

I have a short hose connected to the flush.

I use the same hose I use for water if dumping at my site.. I let it run a few minutes after disconnecting to flush it.

I recommend getting a short clear extension so you can see what is coming out.

I think it works best to turn on the flusher and open the valve until the flow slows down. Then I shut the valve and let it fill up 4-5 minutes then open the valve again. Repeat several times until no more tp or stuff comes out. I drain the gray in between filling the black saving some for the final rinse.

I was surprised how much stuff comes out after it drains the first time.

Your factory installed black tank flush will have its own dedicated built in back flow prevent valve. It's part of the system....