Black tank Flush problem

[Sonoma Sam]

Originally Posted by gkehman

I had the same problem but not right off the bat. Mine worked at one time but stopped. No water was getting past the backflow preventer. I bought a replacement ($58.00) and it is installed but I have not had a chance to test it yet. Just so you know---I was unable to blow air through the new one either and I tried it on several that were on display. There is a ball valve that is spring loaded and it closes very snug. It would take significant water pressure to open the valve. Don't use a pressure regulator on the hose for the black tank flush.

I understand exactly what your talking about now. This valve has two springs that keep the ball shut depending on direction of flow. Just blowing thru one side is not enough pressure to open it, and sucking from the other side is also not enough vacuum to open the spring loaded valve.

[Sonoma Sam]

Originally Posted by MR.M

I would dump it and get a check valve in there instead . the atmospheric back flow they use is fine but if it fails it could dump water into the unit while flushing . since you have it out anyways just bite the bullet and do the check valve

I agree, as soon as my warranty period is done, Ill be changing this out with something more reliable. Think its time to start a list of future upgrades to do when the warranty expires.

[Sonoma Sam]

So now that I am a little more familiar with this valve. It appears to me that it is a combination of a backflow check valve and a vacuum breaker. as it does not allow back flow to flow back in the direction of the inlet but it does allow air for a vacuum break to enter the tank if a vacuum is drawn from inside the tank,
do you guys think this will be a good replacement, When I decide to change it.
https://www.amazon.com/Cash-Acme-173...XBGVNRAKSEMZHZ

[bubbles]

Originally Posted by Sonoma Sam

So now that I am a little more familiar with this valve. It appears to me that it is a combination of a backflow check valve and a vacuum breaker. as it does not allow back flow to flow back in the direction of the inlet but it does allow air for a vacuum break to enter the tank if a vacuum is drawn from inside the tank,
do you guys think this will be a good replacement, When I decide to change it.
https://www.amazon.com/Cash-Acme-173...XBGVNRAKSEMZHZ

Your assessment of what it is, is correct. However; the vacuum breaker is to empty the valve cavity and allow the residual input water to flow back out the inlet port and empty that tubing as it shuts off the inlet side of the valve. The check valve (ball/spring loaded to close the port) shuts off the output side when input pressure is removed. The holding tank is vented to ambient and a vacuum within the tank is a moot point. The valve should be a minimum 6" above the highest usage item (toilet rim)(mine is 4 1/2' above the floor) and why people are so concerned about this particular valve is a mystery to me. In my unit it's overkill.

[5picker]

Originally Posted by Sonoma Sam

So now that I am a little more familiar with this valve. It appears to me that it is a combination of a backflow check valve and a vacuum breaker. as it does not allow back flow to flow back in the direction of the inlet but it does allow air for a vacuum break to enter the tank if a vacuum is drawn from inside the tank,
do you guys think this will be a good replacement, When I decide to change it.
https://www.amazon.com/Cash-Acme-173...XBGVNRAKSEMZHZ

That's the exact replacement I purchased.

[Mr. Dan]

Originally Posted by Sonoma Sam

So now that I am a little more familiar with this valve. It appears to me that it is a combination of a backflow check valve and a vacuum breaker. as it does not allow back flow to flow back in the direction of the inlet but it does allow air for a vacuum break to enter the tank if a vacuum is drawn from inside the tank,
do you guys think this will be a good replacement, When I decide to change it.
https://www.amazon.com/Cash-Acme-173...XBGVNRAKSEMZHZ

Now... where have I heard that?

Originally Posted by Mr. Dan

The flush nozzle is not backwards but the vacuum breaker/check valve has been known to be installed backwards. It’s somewhere above the water level of the commode— sometimes under the bathroom sink cabinet.

[5picker]

Originally Posted by Mr. Dan

Now... where have I heard that?

You must be talkin' to yourself again...

[Mr. Dan]

Originally Posted by 5picker

You must be talkin' to yourself again...

Yep... watching a guy on TV catching 1 ton crocodiles in Australia and talking to myself.

[Iwritecode]

Originally Posted by Sonoma Sam

I agree, as soon as my warranty period is done, Ill be changing this out with something more reliable. Think its time to start a list of future upgrades to do when the warranty expires.

I wouldn't worry about waiting for the warranty to be up. Change it now.

I've never heard of anyone getting their repairs denied because they replaced a faulty check valve.

[Clamper]

Before I leave on trips Ill add 10-15 gallons of water through the toilet into the Black Tank and then add a 20 lb bag of ice into the Black Tank via the toilet. As I drive, the ice will agitate and wash any "material" off the walls. Ill find a dirt lot near destination and dump Black.
Ill empty Black and Grey at home after the trip. My panel usually shows the Black at 1/3 full even after I flush the Black with the hose. Using the Ice While U Drive method almost always cleans the whole tank and I get a empty reading once I dump that water.

[ronrox18]

I had same exact problem and found backflow preventer was installed backwards. Look closely and you will see arrow indicating correct flow direction

[carpenter3129]

problem and it was my hose that goes from the outside to the tank was pinched

[alain h]

Originally Posted by Sonoma Sam

Hello friends
Well the wife and I went on our first shakedown camping trip. A little two day escape only about an hour from home. I threw everything at the trailer to see how it all worked and I am very pleased with how the Sonoma 167rb faired. I ran it on full hookups and also on dry camped the last day. So the only one issue I ran up against, We did our first black and grey water dump at the dump station, everything went smoothly. I then wanted to hook up the water to the automatic tank flush of the black tank, I twisted on the hose to the inlet and I turned on the hose to start washing/flushing the black tank, I heard nothing like water was not flowing into the tank, I removed the water hose and made sure water was flowing good, I hooked it up to the trailer and turned it on again, nothing no water was going into the tank, I waited a few minutes went around and opened my black tank valve, and nothing came out, the water was on into the flush tank but no water was coming out of my black tank. Its like the flush tank inlet is plugged or their is another valve somewhere I missed to turn the sprinkler on inside the black tank, HELP. could something have plugged it up, this is the first time I used it. Their is a small screened washer where I hook up the hose and that was installed properly and not plugged at all, Well I ended up running the hose inside the trailer and filling the black tank up thur the toilet all the way full and then emptied it out again. I tried the black water flush one last time and it still would not let me put water in the black tank. HELP, did I do something wrong? any ideas on what I can try. Oh when we got home, I got my shop vac and put it up to the inlet where the hose goes and try to suck up anything that may be in the line. I did the vacuum with and without the black tank valve open, and still didn't help. What did I do wrong? Did I make another stupid newbie mistake?

I have the same problem
We have a brand new Vibe 224 Rls
This fall to winterized the unit I use air to flush the tank flush
I started at 40 psi then 60nothing then 80 still nothing at 85 or so psi I manage to get the air in
I don’t know about you but I never saw a camping facility with 100 psi water pressure
So I will guess that the valve is defective

[danking49]

Mine leaked and ruined a chunk of my bathroom floor. Took it out and put a vacuum breaker on my flush hose. It may not be to "code"; but you do what you gotta due with the shabby way todays RV's are built.

[alain h]

What is a vacum breaker

[Kei2thehwy]

You poor guy! Here's how I fixed it: my mechanic said that my black tank flush was actually my fresh water inlet from Municipal Water. If you want to check that out hook your black tank flush up to a white hose turn off your pump and try to run water. If it runs, you had the same problem I did. My 2015 Cherokee had the decals for the fresh water hookup and the black tank flush reversed. I understand it's a common problem with Forest River these days, I don't know why they can't seem to work it out on the assembly line, but it happens all the time. Good luck

[2rad4u]

Originally Posted by Clamper

Before I leave on trips Ill add 10-15 gallons of water through the toilet into the Black Tank and then add a 20 lb bag of ice into the Black Tank via the toilet. As I drive, the ice will agitate and wash any "material" off the walls. Ill find a dirt lot near destination and dump Black.

WTH?

[ijon]

My black tank sensors were messed up when we got the trailer. Put in some of that blaster stuff and proceeded to rinse. I got them so they read right. I could not believe the dried up stuff I got out of there. Makes you wonder if someone at the dealership was using the bathroom.

[drumbum59]

Don't get to flustered yet. Wife and I bought a brand new 2016 FR Sabre Lite 25RL. Tried using the BW flush and it would not work. Didn't want to mess with taking it to the dealer because they take forever so I purchased the black tank clear adapter instead. It worked great. Winterized the camper and last year I thought just for the heck of it I would hook up the BW tank flush on the camper and low and behold it worked. My only thought is the poppet valve (?) that opens the nozzles was stuck and it finally decided to open. On another note I would never buy a unit from the dealer where we purchased ours. They had 2 weeks to do the prep before we did the walk through and what a joke. I doubt they even tried the BW flush on the lot before we took delivery let alone anything else. I don't have high water pressure at my home but after a few tries I was happy to see it works. Doesn't hurt to have the backup adapter you can buy at etrailer.com in case your on board flush won't work. Good luck.

[nomad297]

Originally Posted by alain h

What is a vacum breaker

It is a backflow prevention device designed (mostly) to prevent cross-contamination of potable and non-potable water via an air gap. Most vacuum breakers also incorporate a check valve for added protection. One side of a vacuum breaker is pressurized and the other side flows by gravity.

A very common vacuum breaker that many people have in their homes is the air gap on top of their kitchen sink which prevents any water in your sink and its drain from being siphoned back into your dishwasher. This is the most simple form of vacuum breaker and does not incorporate a check valve. Water is sent up to it via pressure from your dishwasher pump, then, from there, it is sent down to your plumbing drain or disposal via gravity. It will spill water all over your counter when the hose going down to your sink drain becomes dirty and restricted. When this happens, it is doing what it is intended to do.

Bruce