Backflush water overflow

[jeeprubi]

When I backflush, the water is coming out of an overflow outlet under the bathroom sink instead of going into the black tank.

I am thinking that the backflush sprayer inside the black tank must be covered with "stuff" and will not spray.

Two questions:
1. Why is there an overflow for the backflush water line under the sink?
2. Any ideas on how to get the "stuff" off of the spray nozzle in the black tank.

Of course it flooded the bay compartment below the sink.

Thanks

[Skip426]

I take it that this is a new-to-you coach, in the factory plumbing there should be no way that any thing in the black tank should back up to the grey water air break under the sink. The black tank should vent to the roof, so look for any evidence of repair to the plumbing/tanks. Sounds like someone realy messed up during a repair.
You are doing your flush with the black dump valve open
The alternative is that the supply line to the tank sprayer, has been cut in an area that can spray water up under the sink. The grey plumbing in my coach goes trough the floor, and is not sealed, to the water bay, behind the water control panel, a water leak behind the panel could spray up to the floor under the sink ; but a leak in that area would also be visible in the water bay.

[MBnKen]

Scottsdale,
I had the same problem and is common with the cheap little back-flush valve. They tend to stick open and them you get that water spraying under the sink. Another poster said they were able to remove and clean. I could not get mine working.

I went to a Newmar Dealer and they wanted $53.00 for the little plastic part. Crazy.

You can get the part online for $3.32 from Recreation Nation https://recreationnation.me/main/

The part is 1 x
Cast Plastic Waste Tank Flush Valve Assy - $3.32
Part Number: 937020

It is a simple threaded connection on both ends.

[Beacher]

I've had that problem to and with I took the clear plastic valve out it was break at the seam put a new one in and problem solved hope this help. I carry a spare with me how lol

[BFlinn181]

Many coaches have the bathroom sink drain into the black tank to add water to the tank. It is strange that a flush valve would squirt up a drain, through a trap, into the vent on the drain. It would have to be full and overflowing the toilet (lower point) before it should back up into the sink vent! I'd look to see if the water line to the flush fitting on the black tank is connected properly. Those flush fittings can be removed from the tank if you have access to it, but I'd be surprised that it could be clogged since it is a nozzle spraying into the tank, it should clear itself. I think you have a cracked or broken drain.

Clean black tank with 'The Geo Method' by C. Bruni :

https://sites.google.com/site/cbruni/

[jeeprubi]

The water coming out of the water overflow vent under the sink is not black water, but fresh water.

I just don't understand why there would be any type of vent for the fresh water lines.

I bought this coach new and there has never been any repairs done to the water lines.

[MBnKen]

Bflinn,
You don't understand Newmar plumbing.

The black tank flush system does not have anything to do with the bathroom sink. The bathroom sink does not drain into the black tank. The water is not running up in the trap and running out the vent. It is coming out of the black flush check valve that is mounted under the vanity in the bathroom. That valve has a Pex line in and another Pex line out and the unit will be mounted high, just under the vanity counter top. It has fresh water coming into the valve from the water bay inlet. It goes through the 2 valves in the little white plastic check valve unit and then goes down to the spray head at the top of the black tank. Hard water or wear & tear will prevent the valves from opening or sealing properly and some of the water will run out of the top of the valve itself when under pressure.

The tank flush kit I mentioned for $3.32 has the white check valve unit and the spray head that mounts on the top of the black tank. The spray unit will not be the problem....just the white check valve needs to be replaced.

[JC2]

Originally Posted by MBnKen

Scottsdale,
I had the same problem and is common with the cheap little back-flush valve. They tend to stick open and them you get that water spraying under the sink. Another poster said they were able to remove and clean. I could not get mine working.

I went to a Newmar Dealer and they wanted $53.00 for the little plastic part. Crazy.

You can get the part online for $3.32 from Recreation Nation https://recreationnation.me/main/

The part is 1 x
Cast Plastic Waste Tank Flush Valve Assy - $3.32
Part Number: 937020

It is a simple threaded connection on both ends.

The pn & item description in your post shows a price of $19.99. Where did you get $3.32?

https://recreationnation.me/main/con...ush-valve-assy

[jeeprubi]

MBnKen

That was a perfect description. Why is the back flush check valve even in the line? What purpose does it serve? Seems to me that the water should go directly into the black tank.

[MBnKen]

Not sure what happened to pricing since I purchased. Here is the copy of my order:




https://recreationnation.me/drupal/user
Purchasing Information:
E-mail Address:


Billing Address:
KEN

LIVINGSTON, TX 77399

Billing Phone:


Shipping Address:
KEN

WINTER GARDEN , FL 34787

Shipping Phone:
9
Order Grand Total:
$13.52
Payment Method:
Credit card
Order Summary:
Shipping Details:
Order #:
647
Order Date:
11/10/2011 - 07:13
Shipping Method:
Standard U.S. Shipping
Products Subtotal:
$3.32
Standard U.S. Shipping:
$10.00
Subtotal excluding taxes:
$13.32
Florida State Sales Tax:
$0.20

------
Total for this Order:
$13.52


Products on order:
1 x
Cast Plastic Waste Tank Flush Valve Assy - $3.32
Part Number: 937020

Where can I get help with reviewing my order?
To learn more about managing your orders on Recreation Nation, please visit our help page.
Please note: This e-mail message is an automated notification. Please do not reply to this message.
Thanks again for shopping with us.
Recreation Nation
Serving your recreational parts needs.

[MBnKen]

Scottsdale,
I would agree but I believe code requires that the check valve be there to prevent siphon back to the fresh line. Check with Newmar to see if you can just plumb it out (connect both ends of the Pex)...but I think they will tell you it needs to be there.

[BFlinn181]

MBnKen, I guess you're right, I don't understand Newmar plumbing! I defer to you! Replace the check valve, I assume (I know) the check valve prevents back flow from the black tank to the fresh water?

[jeeprubi]

Thanks MBnKen.

Here is a picture of the back flush check valve under my sink for others to see and learn. I sure did not know about this.



The back flush water comes into the line on the left to to check valve and out the 2nd line from the left to the black tank sprayer.

I guess you never stop learning new things about these coaches, and I have a simple one compared to a lot of the bigger rigs.

[MBnKen]

That's it Ben. Also open the link that JC2 posted. You will see it and the spray nozzle for mounting on the black tank. I am fairly certain the nozzle is not your problem, only the check valve.

By the way, did you start to notice more noise than usual from the valve when you were running the rinse? Mine starting "screaming" louder than normal as it was starting to go bad.

Sorry to see that Recreation Nation increased the price. $3.32 was just about right for the plastic involved. $19.99 is starting to sound a bit more like a dealer price but still better than the $53 I was quoted at Independence RV.

Yes, you are correct BFlinn, the valve would prevent backflow from a full black tank back though the Pex to your hose that would be attached to the black flush inlet at the water bay. Perhaps it is time for you to upgrade to a Newmar???