Black Tank Flush Question

[bsmall]

I have one of those black tank clean out that run from the side of trailer where you hook up the water supply line and goes to the black tank and sprays the tank clean. At least that's what the intended design was for anyway. So here is my problem/question about this:
It seems when I hook up a hose to the outside hose connector bib on the trailer, I hear water rushing through into the the black tank like its supposed to. Then I hear a banging sound from the water then it shuts off spraying in the tank. I then kink the hose and release the kink a little and once again I can hear water spraying inside the tank. If I release the kink all the way I hear the water banging near the tank then I don't hear water spraying.
I did an experiment and just turned on the water only 1/4 to 1/2 open and the spraying continued cleaning the tank until I turned the water off. I did the same one more time with the water valve 1/2 open and spray cleaner was working fine, that's when I turned up the water flow and the spray just shut off and nothing going into the tank.

So anyone have any problems like I have describe, and if so what did you do to fix the cleaner?

My only guess is that it might be a bad valve where it attaches to the black tank!

Thanks in advance,
.

[Itsthetwoofus]

We have a wash out on both bathrooms and I found that if you start the water flowing it'll clean it out but, get a clear hose attachment for the tank opening and hook the hose to that. Then you can see what's coming out and when it's clean.
Ours will run clean water for a few minutes and then Whoosh!! comes some that the inside spray will brake loose. It works very well. If you can see what's coming out you'll know how well it works. Good luck.

[sherdep]

subscribed - I take delivery of my unit (2306) wednesday and am intrested in doing the tank clean out - what model do you have? is it the Tornado permanent tank rinser that sells at Camping World for like $30?

My father has the wands you put in the toilet - which he told me he was giving me but I am not sure if I really want to hassle with that or not.

Hope I am not off topic but since it is dealing with a tank rinser I figured I would ask since I am intrested in getting one.

Here is a question for ya - did the tank rinser do it before and just started doing it or did you just install it and just noticed this?
If you have the detachable hose - there is a possibility a mud dobber or wasp biult a nest in the hose and when you have full pressure the nest clog's the end

[bsmall]

Originally Posted by sherdep

subscribed - I take delivery of my unit (2306) wednesday and am intrested in doing the tank clean out - what model do you have? is it the Tornado permanent tank rinser that sells at Camping World for like $30?

My father has the wands you put in the toilet - which he told me he was giving me but I am not sure if I really want to hassle with that or not.

Hope I am not off topic but since it is dealing with a tank rinser I figured I would ask since I am intrested in getting one.

Here is a question for ya - did the tank rinser do it before and just started doing it or did you just install it and just noticed this?
If you have the detachable hose - there is a possibility a mud dobber or wasp biult a nest in the hose and when you have full pressure the nest clog's the end

Actually its done it probably since its been new. I never had the clean out on any other trailer and used the wand you stick down the toilet. However, with this model you cant use a wand due to the plumbing and postion/location of the black tank.
When I first used it after taking delivery thats when I noticed once you hook up your hose line to the side of the trailer and turn the water on full it stops spraying water in the tank. If you shut it off and turn the water supply back on only about 1/4 to 1/2 on it sprays and cleans the tank.
So I didn't know if that's how everyones is and its normal or I have an issue with the valve where it screws into the black tank....

[Herk7769]

There is a one way check valve in the tank sprayer to prevent water from back flowing into the hose and contaminating the source water. As you may have found out, if the pressure in the tank backs up it can close the check valve.

My guess is that there is a significant amount of water in the tank when you turn on the flush unit (above the level of the turbo flush so that it is under water). Full blast, perhaps the water is pressurizing the tank and closing the valve; thus stopping the flow.

This is only a guess since mine works just fine.

I have a clear elbow on my hose and dump the black tank completely first as normal (just brown dribbles).
Then I turn on the black water hose full blast and let it run until no more large pieces are seen.
I then close the black valve and let the turbo flush fill the black tank for about 30 seconds (about 1/4 full) and then open the valve again. More junk will come out.
I repeat the above until no more pieces of poo or paper are seen and clear water is all that comes out.
Then I dump the gray water to flush out the hose.

Sent from my iPad using Forest River

[bsmall]

Originally Posted by herk7769

There is a one way check valve in the tank sprayer to prevent water from back flowing into the hose and contaminating the source water. As you may have found out, if the pressure in the tank backs up it can close the check valve.

My guess is that there is a significant amount of water in the tank when you turn on the flush unit (above the level of the turbo flush so that it is under water). Full blast, perhaps the water is pressurizing the tank and closing the valve; thus stopping the flow.

This is only a guess since mine works just fine.

I have a clear elbow on my hose and dump the black tank completely first as normal (just brown dribbles).
Then I turn on the black water hose full blast and let it run until no more large pieces are seen.
I then close the black valve and let the turbo flush fill the black tank for about 30 seconds (about 1/4 full) and then open the valve again. More junk will come out.
I repeat the above until no more pieces of poo or paper are seen and clear water is all that comes out.
Then I dump the gray water to flush out the hose.

Sent from my iPad using Forest River

Thanks Lou, the only thing is that I emptied the black tank out completely befroe connecting the hose to the side of the trailer. I then keep the gate valve in the open position like the sticker on the side of the trailer says to. Once I turn on the water hose I can here the spraying and a little bit of water and waste comes out so I am assuming that the tank is empty. However, I will try elevating the right side of the trailer to a level that will for sure drain the tank. Then hook up the water line turn it on and see what happens. Its funny that once it stops spraying I can partially kink the hose and it sprays just fine with the kink in the hose. So thats why I was thinking maybe the problem is with the Back Flow Preventer where it screws into the side of the black tank.....

[Herk7769]

Originally Posted by bsmall

I then keep the gate valve in the open position like the sticker on the side of the trailer says to

Yes, Bill it sure does say that. If you do not feel comfortable with ANYTHING you read in this forum (or any other); DON'T DO IT.

The reason for that sticker, of course, is that you can put a lot of water in that tank very quickly with that valve closed.

You can mitigate this risk by:

1) START EMPTY - Do a complete dump and leave the valve open. Turning the water on first with a closed valve and a full or nearly full tank will shoot crap water out the roof vent quicker than you can say "What the ?"

2) Instruction manuals try to cover every level of user from pure novice to experienced user and seldom satisfy anyone; let alone every one. Safest course is best when writing manuals.

3) We talk about always dumping with a full or near full tank for a reason. The rush of water helps break up clumps and clogs.

4) Did I mention "Start Empty"; Having a known start point and watching how much water you shoot in there will prevent you from overfilling and making a mess. (or worse pressurizing the tank and bursting a seam).

[Herk7769]

I also think you could have a clogged check valve in the turbo flush as well.

[bsmall]

Well I followed my water line for the tank wash out and located the Back-Flow-Preventer (BFP) valve under the sink in the bedroom. I removed the original plastic BFP and replaced it with a brass one. It now works perfectly. Here are some pictures of before and after:

[MtnGuy]

I think maybe the black thing-a-ma-jingie is an anti-siphon device.......but I don't know why a check valve wouldn't work.

[bsmall]

Originally Posted by mtnguy

I think maybe the black thing-a-ma-jingie is an anti-siphon device.......but I don't know why a check valve wouldn't work.

Hi Chap, I did some investigation of the original BFP and what I found led me to believe why it would work as long as the water pressure was low:
This is a picture of the original BFP and all of its internal parts. And here is what I think was happening with the original one.
In the picture you can see the little piece of white plastic. That piece pushes into the BFP after the spring and ball are in place. What I found was that the little white plactic piece would come out of the BFP and slide into the water line where the collar nut was. This would allow for room for the spring to enter behind that plastic piece causing the ball to travel further then it was designed to. That's when ball would jump back and forth causing the water to bang and closing off the water supply. Then in my case if you would kink the hose line going into the trailer the ball would re-set. That's when I would release the kink slowly and would here the water cleaning the inside of the tank. Once I would release the kink compeltely the ball would start bouncing back and forth creating the banging sound and then seal in the closed position, thus allowing no water to enter into the tank.... Hope this all makes sense.
With the brass BFP all of its internal parts can't be removed so life is good...

[Herk7769]

Bill,

I just checked and have the same unit, mounted the same way, in my camper. I never noticed the buzzing noise of the turbo flush stops occasionally here as well. Your fix is on my summer "to do" list.

Thanks,
Lou

[bsmall]

Originally Posted by herk7769

Bill,

I just checked and have the same unit, mounted the same way, in my camper. I never noticed the buzzing noise of the turbo flush stops occasionally here as well. Your fix is on my summer "to do" list.

Thanks,
Lou

Glad to have helped you out Lou. I also located this BFP from Tweetys RV, but didn't order it and just stayed with what others have used. I think the only difference is that it has male threads on both ends. This would have have saved me one fitting only. Here is a pic of that one:

[Herk7769]

Bill, could you post the link to that fitting? I will order it when I get home.
Lou

[bsmall]

Originally Posted by herk7769

Bill, could you post the link to that fitting? I will order it when I get home.
Lou

Here is the link to the male threads on both ends:
Back Flow Preventer

Here is the link to the one I used (Check Valve, 1/2" MPT x 1/2" FPT ):
Check Valve, 1/2" MPT x 1/2" FPT

Cheers,

[bsmall]

Hey Lou did you get the info on the valves???

[Herk7769]

I did. Thank you. It is on my "to do" list for next week when we get home.

[bsmall]

Good luck to you with the replacement valve.....

[WestCoastRV'er]

Do you need to use a water pressure regulator on the black water flush outlet.

It was recommended by my dealer to use a seperate hose for just this purpose but they never mentioned if I needed a water pressure regulator.

[Herk7769]

I do not. I figured the more pressure the better.