Newbie Question- A bit confused about the BLACK TANK

[Road.Trip]

Hello community!

We bought a 2019 International Serenity in January before Covid changed all our lives. We are finally on the road 24/7 and trying to understand all the in's and out's of RVing-

We understand the basics of the grey and black tank. However, when we try to hook up the black or garden hose to spray inside the black tank, the hose pops off and the label says:

"Do not use the tank flush valves unless the fullway termination valve is in the open position. May result in an unsanitary condition leading to illness or personal injury.

We are clueless and have watched numerous videos, and read through the manual. Seems so easy- just attach hose but for some reason, its not so easy for us.

THANK YOU!

[BayouBiker]

The warning label is trying to tell you not to use the tank clean out with the Black tank dump valve closed. If you do and forget to open it after about 5 minutes the tank could overflow out the toilet and into the trailer if the toilet bowl dump valve leaks and out the roof vent stack and all over the place also.

Now your more immediate issue seems to be the hose threads or the clean out threads may be damaged. Inspect both carefully to see which might be bad.

[Daquenzer]

1. Empty black tank.
2. Empty grey tank
3. Attach hose to flush then turn it on and run it.

I close the valve on black tank and let the water fill tank a bit; say a minute. Then I open black valve and let it drain. I do this a few times. Then I let the water run until the water is pretty clear. I realize this is not kosher. But it works great.

You should get a clear attachment so you can see the water coming out of the tank.

Do not use the flush UNTIL the black tank is empty!!

[ROBERT CROSS]

I hook up to the flush fitting, go inside, turn off the water pump, stick the toilet bowl cleaning brush in the bowl to hold the valve open. Turn on the hose. Back inside, put in 1oz of Dawn, when I see bubbles up the hole turn off the hose.
Let sit & dump next morning. (use the house sewer cleanout)

Bob
🇺🇸

[OTRA15]

Originally Posted by Road.Trip

. . .
. . . when we try to hook up the black or garden hose to spray inside the black tank, the hose pops off . . .
. . .

Welcome to the forum!

It is possible that the prior owners did not use the black tank flush system frequently, and that the tiny orifices [in the spray jet heads inside the black tank] are clogged with fecal material. When you turn the hose on, the water pressure is so high that it forces the hose to pop off.

There is no easy way to clear them out, as I understand it, without removing the black tank and swapping in new spray heads IMO. [Cost >>> reward]

"black tank flush spray heads clogged: -- https://www.google.com/search?q=blac...=airforums.com

You could ask the previous owners about this.

Good luck,

[uncle_bob]

Hi

Even if the spray is plugged up, the hose should not *pop* off of the fitting on the trailer. Are you using some sort of quick disconnect on it? If so, get rid of the QD and just thread onto the threads. If you *are* on the threads, either they or your hose end are damaged. One or both need to be replaced.

If the spray holes are gummed up, fill the black tank with (clean) water and some dishwashing soap. Let it soak for "a while" (is that hours, days, weeks .... hmmm....). After it's soaked a bit, try the flush wand again. This is a might help / can't hurt sort of thing rather than a sure fire solution.

Bob

[bibbs]

If you are actively using the toilet, as you would when full timing, back flushing is not needed.

[matthewk]

Originally Posted by Daquenzer

1. Empty black tank.
2. Empty grey tank
3. Attach hose to flush then turn it on and run it.

I close the valve on black tank and let the water fill tank a bit; say a minute. Then I open black valve and let it drain. I do this a few times. Then I let the water run until the water is pretty clear. I realize this is not kosher. But it works great.

You should get a clear attachment so you can see the water coming out of the tank.

Do not use the flush UNTIL the black tank is empty!!

1. Empty black tank.
2. Attach hose to flush then turn it on and run it.
3. Empty grey tank

Grey tank last to washout anything from the black tank left in the hose. The sprayer volume won't fully fill the sewer hose and get all the black remnants out.

[Wazbro]

Did the tank flush ever work?
There have been reports of the check valve being installed backwards from the factory.

[guskmg]

Airstream techs used J C city water pressure to blow mine and it worked. Finding higher city water pressure may be a problem where you live, so you might be forced to let it soak full with soapy water a few days. I wanted mine cleaned out so I could use the onboard water pump to spray it out when city water was not available.
guskmg

[Mikebrady62]

Road.Trip
I have the same model and year AS. Does your hose seem to thread on and tighten up? Can you pull it off with a firm tug? If it stays on fine, that is a lot of pressure being built up. Take it in for a warranty repair. (it's covered for 3 years)
BTW I close my valve and fill the tank to about 70% a couple of time to get a good rinse, then throw a sanitizer in and a couple gallons of water and travel to the next location. Seems like the sloshing around helps get all the TP off the tank walls.

Good luck!

[Snaken49]

There is a one way check valve located on the inside wall of your Airstream that prevents the black water from coming back into your flush hose.


If this valve becomes stuck and they do your fresh water hose will pressurize and the system will not work. It seems the valve can stick from non-use. I had to replace one on my 2010 FC, rear bedroom.



It was located under the sink on that model.


Good luck! Snaken49

[Ella]

Originally Posted by OTRA15

Welcome to the forum!

It is possible that the prior owners did not use the black tank flush system frequently, and that the tiny orifices [in the spray jet heads inside the black tank] are clogged with fecal material. When you turn the hose on, the water pressure is so high that it forces the hose to pop off.

There is no easy way to clear them out, as I understand it, without removing the black tank and swapping in new spray heads IMO. [Cost >>> reward]

"black tank flush spray heads clogged: -- https://www.google.com/search?q=blac...=airforums.com

You could ask the previous owners about this.

Good luck,

If you suspect this is the problem, dump the black tank, put a bag of ice cubes (the kind you buy at the gas station) down the toilet. Add 8 litres of water and a black tank puck or crystals. Go for a drive for an hour and then dump the black tank again. The ice will swish around the tank and clean up any debris. This is also a great procedure for trailers that do not have a black tank flush system.

[uncle_bob]

Originally Posted by Ella

If you suspect this is the problem, dump the black tank, put a bag of ice cubes (the kind you buy at the gas station) down the toilet. Add 8 litres of water and a black tank puck or crystals. Go for a drive for an hour and then dump the black tank again. The ice will swish around the tank and clean up any debris. This is also a great procedure for trailers that do not have a black tank flush system.

Hi

If you are going to try using ice to clean the flush wand, get several bags. Simply sliding around in the bottom of the tank isn't going to help that wand much ...

Bob