Black Tank

[tommy230635]

Hello ! I have to check the water inlet (flush) of the black water tank, because if I open the valve to flash my tank, the water flows under my fifth wheel. How to access the black water tank. My equipment is a Fifth Wheel Rockwood Signature Ultra-Lite model 8244S.
Thanks if you can help me!
Ronald

[Skip12]

If you get clean water when you attempt to flush your black water tank, see if your antisiphon valve is leaking. That's exactly what happened to me.

It looks like this and will likely be near where the water enters the camper, near knee high level.

https://www.amazon.com/dp/B07P75Y1MR..._-1WTEbHR7P12C

When folks replace these, they often upgrade.

[rockfordroo]

The valve Skip12 is describing is plumbed like this:



The valve is often under a bathroom sink.

But if you're getting water from underneath, that sounds like a hose line isn't properly hooked up.

[Mr. Dan]

X2 — and this valve is actually elevated higher than the top rim of your toilet bowl.

[tommy230635]

Hello ! If I open the water to rinse the black water tank, there is no valve leak (no: 3 vacuum breaker-check valve). The water flowing under the fifth whell seems to come from the black water tank, perhaps because of the pressure accumulated during my last rinse and that I forgot to close the water inlet a few minutes to rinse . The valve shown in the diagram (no: 5 Flush) has probably broken. So if I had a tank diagram to know where is (no: 5 Flush), I could cut an access under the fifth wheel to have access to this tank without having to remove everything below!
Thank you for your help !
Tommy

[fonzie]

What year is your fifth wheel?

[tommy230635]

Fifth Wheel Rockwood Signature ultra-lite 8244S année 2012
Merci !

[fonzie]

Originally Posted by tommy230635

Fifth Wheel Rockwood Signature ultra-lite 8244S année 2012
Merci !

OK, have a look underneath your bathroom vanity or underneath your TV cabinet by opening the two lower doors. Look for this...

[WFD]

There should be no pressure accumulated from your last rinse. Your black water flush is simply is a water line leading to spray heads within your black tank that spray a water jet stream against the walls of the tank. Once shut that line simply drains and there is no residual pressure left behind.
This water leaking under your trailer....I assume it's clean water? If so than it's leaking from somewhere before it enters the black tank.

[tommy230635]

Yes, it is placed in the cabinet under the sink!

[tommy230635]

Hello WFD,
that's why I want to have access to the tank without removing the entire underside of the fifth wheel! Perhaps the sprayer is torn from the wall of the tank!
Thank you

[WFD]

Not so sure you will be able to get a diagram of any sort. I think if you want to get a visual of what's going on at the tank you will need to remove a large section of the underbelly and then re attach when you are done. Many here have reported doing that to inspect the strength of their freshwater tank supports. They have either cut inspection holes in the underbelly and then installed supports to re-attach the plastic underbelly or loosened a large section of it and re-attached.

[tommy230635]

Thank you WFD, your help is greatly appreciated!
Tommy

[rockfordroo]

Originally Posted by tommy230635

Hello ! If I open the water to rinse the black water tank, there is no valve leak (no: 3 vacuum breaker-check valve). The water flowing under the fifth whell seems to come from the black water tank, perhaps because of the pressure accumulated during my last rinse and that I forgot to close the water inlet a few minutes to rinse . The valve shown in the diagram (no: 5 Flush) has probably broken. So if I had a tank diagram to know where is (no: 5 Flush), I could cut an access under the fifth wheel to have access to this tank without having to remove everything below!
Thank you for your help !
Tommy

No. 5 is not a valve. It's just a fitting on the tank where the water comes in. Depending on the exact model, it MAY include a spinning cylinder inside the tank with holes to spray the water around. See pic below:



In either case, it's not your problem UNLESS the hose has disconnected from the fitting.

Also, if you have the black tank drain valve open like you're supposed to, there should be little to no pressure inside the tank.

(Note that the system in the pic just uses a check valve (the round black thing in the middle of the pic) instead of a vacuum breaker valve as in the other pics we've provided.)

[glen1971]

Originally Posted by rockfordroo

No. 5 is not a valve. It's just a fitting on the tank where the water comes in. Depending on the exact model, it MAY include a spinning cylinder inside the tank with holes to spray the water around. See pic below:



In either case, it's not your problem UNLESS the hose has disconnected from the fitting.

Also, if you have the black tank drain valve open like you're supposed to, there should be little to no pressure inside the tank.

(Note that the system in the pic just uses a check valve (the round black thing in the middle of the pic) instead of a vacuum breaker valve as in the other pics we've provided.)

I'm not advocating to flush the tank to a closed valve, but you won't pressure up the tank unless the vent line to the roof is plugged. We drain the black tank, flush, close the valve, partially fill, then drain, repeat, then shut off the flush, then move to the grey tank..

Found this write up on RV plumbing that seems to have a lot of good info..

https://www.trailerlife.com/tech/abo...-waste-system/

[rockfordroo]

Originally Posted by glen1971

I'm not advocating to flush the tank to a closed valve, but you won't pressure up the tank unless the vent line to the roof is plugged. We drain the black tank, flush, close the valve, partially fill, then drain, repeat, then shut off the flush, then move to the grey tank..

Found this write up on RV plumbing that seems to have a lot of good info..

https://www.trailerlife.com/tech/abo...-waste-system/

Good point. Always forget the vent - it's out of sight/out of mind.

[tommy230635]

Thank you rockfordroo and glen1971!
The hose may be disconnected from the fitting (glen1971). Note that if I am not using this cleaning system, I have no problem with this tank. All because I forgot to open the tank drain valve!
This week, (weather permitting) I'm getting to work, and I'm giving you news!
Your help is very useful to me!
Ronald

[bubbles]

Originally Posted by tommy230635

Thank you rockfordroo and glen1971!
The hose may be disconnected from the fitting (glen1971). Note that if I am not using this cleaning system, I have no problem with this tank. All because I forgot to open the tank drain valve!
This week, (weather permitting) I'm getting to work, and I'm giving you news!
Your help is very useful to me!
Ronald

If you have a factory installed black tank cleanout, not opening the drain valve will not cause your issue.

[tommy230635]

Thank you for your advice ! The hose that connects to the black water tank seemed to be loose. And also, I noticed that the two hooks that hold the two tanks (black water, and used water) were off the hook. Everything is now repaired!
Best regard !
Tommy