Black Tank Flush?

[lp722]

Out of curiosity...my 291RK has a flush valve for the black tank. How does this actually work? Is there actually some sort of high-pressure spray nozzle inside the tank that blasts the sides, or does it just dump extra water into the tank without you having to fill from the toilet?

[harley]

first off , dont put the tap(hose) on full ,just enough to put water thru,maybe 1/2 way. Mine leaks a bit at the aeroator (under the bath sink) if to much pressure.
It is just a nozzle in the upper portion of the tank on one side. There is an aerator between the outside fitting and the tank ,usually under the sink. This part is never checked a the factory or at most dealers and will probably have 2 loose hose connections. There is an arrow on it that should be facing the direction of water flow,some have been installed backwards.Look under the sink and tighten .Watch under there while someone turns the water on .
some say to only use when valve is open ,others do when valve is closed. If vent is hooked up correctly ,either way will be ok,as the vent will expel air when water is filling.
If you are at a full hookup site then it will work good to flush tank when you dump ,but if you are at a dump station ,there are alot of stations that do not have a hose fitting so a 5 gal water container dumped into the toilet bowl is better,and quicker. fill the jug up before you get to the dump station to save time.

[sleepyT]

Lp
Before you are ready to dump your black water tank using the flush, the first thing you want to do is to purchase a clear plastic extension pipe that attaches between the 3 inch camper waste pipe and your flexible dump pipe...You will use it to determine how dirty or clear the black tank is as you flush...This clear pipe can be bought art any RV store...

1) attach the campground fresh water to the flush, open the black water dump valve and turn on the flush at the same time...
2) watch the waste water through the piece of clear plastic pipe, when the black water slows down close the black water dump valve while letting the flush run for a couple of minutes, then reopen the black water valve...
3) repeat this process until the water coming out of the black tank, as seen through the clear plastic pipe, is fairly clear...

WARNING::O NOT walk away from this process until you are finished dumping...If you start something else and forget you are dumping you could flood your camper...I've seen it done NOT pretty...

[lp722]

Thanks guys. I do understand what the process is, I was just curious from a functional standpoint how that flush valve works, e.g. is it just adding water into the black tank, or is there actually a spray valve that pressurizes the water and blasts into the black tank to clean the walls off?

[harley]

As I mentioned in my long winded info, just a nozzle pointing at the other wall.

[lp722]

Originally Posted by harley

As I mentioned in my long winded info, just a nozzle pointing at the other wall.

Got it, thanks Harley!

[sleepyT]

Originally Posted by lp722

Thanks guys. I do understand what the process is, I was just curious from a functional standpoint how that flush valve works, e.g. is it just adding water into the black tank, or is there actually a spray valve that pressurizes the water and blasts into the black tank to clean the walls off?

Lp
OOOPPS thought you were asking how to use the flush...

[frosty42]

I have the black tank flush on my unit and it does work very well. After the initial drain of the tank, I close the valve and use the flush to fill the tank. I usually have the wife go inside and use the indicator panel to tell me when the tank is 2/3 full. I will then re-open the black tank and drain. I repeat this process probably 2-3 times before closing everything up. Keeps everything clean and clog-free.

It baffles me why so many dump stations have a silly "J" nozzle attachment thingy that is useless when you have an external flush connection. Some locations will remove the set screw from the nozzle so that you can remove it and attach your own hose for the black tank flush. Word of the wise....do not use your fresh water hose for this process. Get a separate 20' section of hose dedicated for black tank flushing.

[travelin texans]

I would NEVER EVER trust any of my tanks to read any where near accurate, especially while filling the black tank. Filling the black for 3-5 minutes on mine is more than enough to sufficiently clean it. After the initial dump I squirt a healthy squirt of some cheapo dish soap down the toilet & then rinse/dump a few time til clear.

[dminer04]

The manual for my ST32BH advised me to run the faucet for the outside sink while using the flush. This is also a benefit because when I see the water in the sink back up I know its full.

[Lloyd]

Originally Posted by dminer04

The manual for my ST32BH advised me to run the faucet for the outside sink while using the flush. This is also a benefit because when I see the water in the sink back up I know its full.

You must have one of the few that CR plumbed into the holding tank. Thats great!
But I think you should count your self lucky and fortunate to have thay feature.

[dminer04]

So all the sunsets don't do that? Where does yours drain?

[Lloyd]

Here is just a little reading on that topic.

http://www.crossroadsowners.com/foru...und-12413.html

http://www.crossroadsowners.com/foru...ain-11425.html

http://www.crossroadsowners.com/foru...hen-11376.html

http://www.crossroadsowners.com/foru...ain-11204.html

[harley]

My flush is connected to the black tank . All sinks including out kitchen goes to grey tank.

[Steve7]

Originally Posted by dminer04

The manual for my ST32BH advised me to run the faucet for the outside sink while using the flush. This is also a benefit because when I see the water in the sink back up I know its full.

I hadn't heard of this before. I'm assuming your outside sink drains into the black tank? So are you closing the outlet valve, and then watching for "black tank" water to back up into outer sink?... I must be misunderstanding this.

[Steve7]

My outside sink drained to the ground!...I never used it.

[dminer04]

Wow... Ya my outdoor kitchen sink is plumbed into my black tank. It makes it very convenient when we are camping without sewer so my grey tank doesn't fill up as quick.

[breams]

Originally Posted by harley

first off , dont put the tap(hose) on full ,just enough to put water thru,maybe 1/2 way. Mine leaks a bit at the aeroator (under the bath sink) if to much pressure.
It is just a nozzle in the upper portion of the tank on one side. There is an aerator between the outside fitting and the tank ,usually under the sink. This part is never checked a the factory or at most dealers and will probably have 2 loose hose connections. There is an arrow on it that should be facing the direction of water flow,some have been installed backwards.Look under the sink and tighten .Watch under there while someone turns the water on .
some say to only use when valve is open ,others do when valve is closed. If vent is hooked up correctly ,either way will be ok,as the vent will expel air when water is filling.
If you are at a full hookup site then it will work good to flush tank when you dump ,but if you are at a dump station ,there are alot of stations that do not have a hose fitting so a 5 gal water container dumped into the toilet bowl is better,and quicker. fill the jug up before you get to the dump station to save time.

Hello,
Could you show a picture of the Aerator valve and how you determine if it is in backwards? My blackwater tank flush does not work at all.

[harley]

My flush didnt work at first either as I later found out there was a kink in the hose from the aerator to the tank . The pressure would build up and leak under the sink . I cut the underbelly and found the kink and added 2' of hose and works ok now.
Look under your bath sink with a flashlight and look for an arrow on the side of the black 90 degree aerator showing water flow direction.
Dealers never check these things even on the pdi unless you ask them and they actually go to the trouble of getting the garden hose out.