Mod in water compartment

[boowho]

Originally Posted by Phil57

I mostly wanted your opinion and I thank you for that.

Phil, you sure got'em!!

Boowho??

[bob caldwell]

Originally Posted by bubbles

I'm not going to do the mod but the black tank is vented and there is this big hole coming thru the floor called a toilet. If the black tank is installed correctly there is no way for backflow to occur (my opinion). This is a typical rv cleanout I believe:

Why not do away with plastic backflow valve in the drawing, and buy a brass one and insert it between the inlet and flusher, doing away with excessive hose and a valve, when it fails, would let black tank fumes into lavatory?

[Jim in Halifax]

I use the "Y" setup....main water hose to input and two short pieces of hose to each input.......When I want to flush out black tank I shut off the fresh water side and then open up flush side.....and vice versa.........I cannot see how any contamination can occur to the fresh water system within the RV..Water pressure "in" is greater than any pressure "back"....Tank is vented!!!!.....J

[j free]

I don't see how it could back flow up 3 feet from the tank level and in my rv's case another 28 feet forward from the tank to cause any problem. If someone has over filled there black tank that much then they have a much bigger problem in the bathroom and they should not be rv'ing.

[tkdavis]

Here is a pic of mine...using a "Y" between the City Supply and Fresh Fill. Also added brass high flow quick connects to make hose connections easier. I usually only back flush the BT at home after trips and keep a dedicated hose for that purpose. For me, I see no need to have a common connection to the BT Flush, adds risk for not much reward.


Terry & Kim
2015 Forest River Berkshire 38RB
2007 Wrangler Unlimited

[Ditchdigger]

Back flows occur, when you get negative pressure in the water main(or what you are filling with)which can happen with a broken line in the water system, which causes a vacuum in the line. I worked for the Seattle Water Dept. for 30yrs so I know about cross-contamination, and I would not hook up my potable water to any non potable water even with a back flow prevention device, because I have seen them fail. Unless you want to spend A lot of money on a legal on, and a 3/4" one will cost in excess of $50 or more, I would trust a cheap one. Most of the trailers that have the tank flush system do have a vacuum break system but they are not a back flow preventer. they help but are a minimum safety device. It does not take that much more time to take off the flushing hose and put on a fresh water hose. Mine is stuck back up where I can't even see it, I have to feel for it. I am going to move it to the out side of the trailer to get it away from the potable water. FR has a bad design.

[bubbles]

Originally Posted by bob caldwell

Why not do away with plastic backflow valve in the drawing, and buy a brass one and insert it between the inlet and flusher, doing away with excessive hose and a valve, when it fails, would let black tank fumes into lavatory?

If the rv comes with a BT clean out the manufacturer has installed it in accordance with (IAW) IAPMO TSC-27 which requires the check valve to be a minimum of 6" above the highest flood level rim of any fixture connected to the waste holding tank.The clean out nozzle in the tank is within 2" maximum from top of tank. There are aftermarket clean outs and they work great and are not required to be installed IAW any standards (a DIY) but if manufacturers are going to install one they must follow existing standards and FR does, as far as I can tell.

[5456Mich]

Originally Posted by tkdavis

Here is a pic of mine...using a "Y" between the City Supply and Fresh Fill. Also added brass high flow quick connects to make hose connections easier. I usually only back flush the BT at home after trips and keep a dedicated hose for that purpose. For me, I see no need to have a common connection to the BT Flush, adds risk for not much reward. Attachment 89668


Terry & Kim
2015 Forest River Berkshire 38RB
2007 Wrangler Unlimited

Now this set up is sexy looking, I can go for that and have a separate hose for the flushing of bt.

[bob caldwell]

Last time I used the tank flusher, it developed a leak in the plastic body where the floating valve inside meets it's seat. When there's no water pressure present, the valve is an open vent into black tank if the check valve fails. If I hadn't had the pass-thru door open, I'd never seen the water leak'n. So, to fix the problem I bought a proper backflow valve ($30 @ HD) and eliminated the plastic one and about 15' of hose. Mounted it just inside the wall, so when disconnecting there will be minimal water present to soak you. The original valve says it's good for 125lbs. and my regulator is set at 45lbs, so it wasn't being over pressurized...it just failed....good luck with yours. Sit'n here look'n at factory valve, it is a backflow valve.

[bubbles]

Originally Posted by 5456Mich

Now this set up is sexy looking, I can go for that and have a separate hose for the flushing of bt.

Sort of reminds me of the FLUX CAPACITOR. I wonder if it glows?

[tkdavis]

Originally Posted by bubbles

Sort of reminds me of the FLUX CAPACITOR. I wonder if it glows?

It does when I put plutonium in it!!! However, I have trouble getting the Berk up to 88mph!


Terry & Kim
2015 Forest River Berkshire 38RB
2007 Wrangler Unlimited

[Lefty59]

I understand the concerns with cross contamination...but unless you always have a non-potable water source to connect the black tank flush to isn't the question more about which potable water system may get contaminated?

If you connect the blank tank flush hose to your home water supply or some other potable source of water the chance for cross contamination still exists...perhaps just a little further away from the RV. Correct?

I always use a back flow preventer on the black tank flush line...but figure if it fails then the potable water source may become contaminated...whether that source be from my RV or some other external supply source.

[tmmar]

So, if I'm a good guy and use a back flow prevention device, then I keep everything safe including the water source. What about the guy before me or the guy before him and so on. If they don't use any thing, how would I know if they something that they did or did not do contaminated the source? Things like this are out of our control and you have to rely on the builders of the coaches that they have devices installed that prevent the back flow from occurring.

[Ditchdigger]

That is why I do not like to fill the fresh water tank at the same hose bib they use to flush the waste tanks. But sometimes it can not be avoided. In the past I have seen people stick the hose up the drain pipe, when flushing their tanks. In Washington the DOT dump sites have a separate Potable water bib, and a sign at the dump site NOT FOR POTABLE WATER.

[gasman94]

Originally Posted by tmmar

So, if I'm a good guy and use a back flow prevention device, then I keep everything safe including the water source. What about the guy before me or the guy before him and so on. If they don't use any thing, how would I know if they something that they did or did not do contaminated the source? Things like this are out of our control and you have to rely on the builders of the coaches that they have devices installed that prevent the back flow from occurring.

Open and flush spigot. Spray with bleach solution and allow to sit while you're hooking up electrical. When ready to hook up hose, open spigot and rinse, then connect hose. If there were some gift left from the previous person, odds are you killed it.


Rich

[Swift 2]

some times my toilet puts a bubble up when the vent is open. Not always and i don't know why. works great sometimes?

[kandl]

Originally Posted by Swift 2

some times my toilet puts a bubble up when the vent is open. Not always and i don't know why. works great sometimes?

Your BT vent may be partially obstructed. The need to know why should be on the top of yer to-do list.