Black water tank flush system

[Indy500]

Originally Posted by Hclarkx

If I can borrow the thread .....

My 2015 Rockwood Ultralite black tank flush seems to work fine (quite an audible spray) but when I turn off the water and disconnect the hose at the black flush female hose fitting on the side of the RV, I get a regurgitation of a cup or two of water under considerable pressure. Is this normal?

I dont really hear the sprayer working , but I do have some water come back out when disconnecting the water hose. I thought there was a lot of pressure on the hose when flushing . Didn't seem to flow like I thought it would

[Indy500]

Originally Posted by Iggy

Actually all the water lines that go into the rig have a small spring loaded one way valve.

Iggy

Thank you

[sherman12]

The owners manual on my Georgetown stated that after using the black tank flush to be aware of pressured excess water after the water hose is disconnected. I would just wait a couple of minutes before removing the hose.

The picture of the black tank flush check valve looks exactly like mine in my Sportscoach. Thanks for the picture because I originally thought it was a shut-off valve for the fridge ice maker!

[KEliasz]

I have had the same issue. My check valve went bad I replaced with a brass one. Also my sprayer was plugged. I filled the tank with through the toilet with hot water from my house and added Caravan sensor cleaner and let it sit for a week. It's now working again

[UYAWNT2]

So I took out my Georgetown out for the 1st time last weekend. I used the Black flush system & it seemed to work fine. Got home & everything was wet in the closet for the close washer where the valve is. Bad valve? Too much pressure??

[bubbles]

Originally Posted by UYAWNT2

So I took out my Georgetown out for the 1st time last weekend. I used the Black flush system & it seemed to work fine. Got home & everything was wet in the closet for the close washer where the valve is. Bad valve? Too much pressure??

Chances are the connections are cocked (or not tight). I think the valve is rated at about 125psi. The pex crimps could also be bad. Connect up the cleanout and have a look see where the leak is happening. I did have a crack in my factory installed one and replaced it. I eventually just took out the valve and jumped the lines together because I wanted the tank to fill faster.

[Hclarkx]

Originally Posted by bubbles

This is normal (amount does vary with where the vacuum breaker/check valve (VBCV) is located within the unit). It's your input fresh water coming back out of the line from the VBCV as the vacuum valve closes off the input side of the valve. In fact that's the reason for the vacuum breaker which is vented to ambient within the VBCV. It's not anything from the black tank.

Thanks. I won't worry about it then. And will try to remember to disconnect the black hose at the other end first so I get less wet.

[jnjac]

Originally Posted by Flybob

The back flow valve is normally in the hose connection on the side of the RV or in the wet bay. Occasionally they are installed backward.

Thanks to Flybob for the hint on the backward install. I have a 2019 GT5 and the black tank flush wasn't working. After reading this thread and Flybob's hint I checked my backflow valve and sure enough it was installed backward at the factory. (I guess it's too much to ask for the factory to do a little QC on their work) Anyway, 15 mins and a couple of shark bites later it's now working. Thanks to all on the thread.

[aztrooper]

Thanks for the replys. I've been busy building the house and haven't had much time for messing with the cleanout on the BWT. I have found the back flow valve in the closet hiding behind the washer machine pvc pipes in the washer/dryer closet. It follows that the inlet for the black tank sprayer would be in the water heater compartment as was shown in the pictures. I have been using Unique black tank cleaner but that has not helped the sensors which show full all the time. We are going to be away for a couple of days so we are going to completely drain the black tank and flush it with a couple toilet bowls full of water then completely fill the tank and add a couple of cups of Unique cleaner along with doing the same thing with the gray water tank just because. When we get back, we will empty them both, flush them out and see if that fixed it. If not, I'm going to get some of the RV sensor and tank cleaner that was mentioned earlier and do the same thing over again. Thanks for the suggestions.
Bob

[sherman12]

https://www.youtube.com/watch?v=0M08l9lYs1A

Bob, this is a youtube link to what they call the Geo Method of cleaning and maintaining your black tank.

Essentially, they use Calgon water softener in the tank along with Borox powdered laundry detergent, and if I remember correctly some Dawn dish detergent.

I have not tried this, I have become a fan of Happy Camper enzyme black tank treatment, Amazon, about $22 for 18 treatments worth. I add a gallon of water and a scoop of HC after every dump so it sloshes around in the tank between camp outings. However, I am intrigued by the Geo Method based on water softener makes sense as does Borox for the cleaning part. And, it should be a less expensive treatment.

[aztrooper]

Thanks Sherman12. We tried that for awhile but since we live in our MH in our steel building while building the house, that got pretty expensive dumping every week into the drain we had put into the concrete floor when the foundation and floor were poured. I don't know if that would have prevented where we are at now but might have. I think that the black tank rinser nozzle is just blocked by "residue" from when it gets up to that height. The sensors are covered also I think because they always read full. We are going to drain and fill it with fresh water and put an extra amount of Unique RV Digest-It Holding Tank Treatment we have while we are gone and see if that clears it.