Hi all. i have one of those rinse/sanitize hookups for the black tank and was just wondering what the proper procedure is. Im new to this. I have seen one video where they installed a backflow preventer on the hose. Do you need this if you use the same hose all the time? It cant get back into your faucet , can it? Also, do you leave the gate valve open on the black tank the whole time? Or can you close it for a while (of course without going anywhere) and then empty and repeat to get the whole tank rinsed well? Im kind of wondering where the water hits inside (hard to tell without being able to see inside tank). Thanks a lot

More commonly called black tank flush. Typically you drain the black tank until empty. Then turn on water to the flush connection. I close my black tank valve for a minute or so to let water build up in the tank, then open the valve to drain again, then repeat another time or two or three until the water is running mostly clear. Usually I see additional "solid material" come out the first time or two of draining during the flush. Just don't go off and forget you left the flush running with the valve closed.There is most likely a antisiphon/backflow preventer valve installed internal to your RV, unless it has been removed (they are prone to failure). An external backflow prevention valve is not a bad idea.There is no sanitizing involved in the process.

After you empty the black tank, turn on the rinser and let it rinse for a minute or so. Open valve and drain. You can leave the water on while you drain. Close the valve for another minute or so, then open again. Do it a third time and your tank is as clean as it's going to get. Close the valve, let your rinser continue for 60-90 seconds to put some water in the bottom of your tank, then turn it off, disconnect and you're good til the next run.Some coaches have a common dump end where both the grey and black use the same end to dump. Mine is like this. I leave the grey open all the time while camping. (We take long showers and do laundry). When the black needs emptying, I close the grey before taking our showers. I then open the black and drain it. Once it's empty, I open the grey valve and allow the warm shower water to flow into the black for 30 seconds. Close the grey and allow the black to empty. I follow the above procedure and after the third time, I allow the shower water to run into the black for about 45 seconds then close that valve and let the shower water empty cleaning the sewer hose as it does. If I forget to close the grey valve, I use the rinser as described above....Dennis.BTW...if you use the rinser and get distracted, water will pour out of your black tank onto the roof of your coach, sometimes with disasterous results....D

After I dump the black tank, I leave the valve open and flush for awhile. Usually there's still solid material, including TP, hanging up at the valve gate. If I close the valve at the end of the first dump, some of that TP tends to get stuck in the valve seat preventing full closure the next time. While flushing, when the water looks mostly clear, then I'll close the valve and do partial fills of the tank to get more solids out.

Bleach is a big no-no! I use the tank flush system til the water runs clear and I have some terrific biodegradable treatment that always keeps it smelling pleasant. Craig

Proper procedure for black tank rinse/sanitize | Good Sam Community

austinjenna
Explorer
Jun 30, 2015
After I added a twist-on Valterra valve to my rig. This allows me to empty the black tank, close the twist-on valve, open the gray water tank's valve, which runs into the black tank. The result is a fast backflush that gets anything out without wasting any water in the process.

Hey that is pretty smart!
mlts22
Explorer
Jun 29, 2015
After I added a twist-on Valterra valve to my rig. This allows me to empty the black tank, close the twist-on valve, open the gray water tank's valve, which runs into the black tank. The result is a fast backflush that gets anything out without wasting any water in the process.
bid_time
Nomad II
Jun 29, 2015
cchristanis wrote:
It was here p.18 under camping with grey valves open section:

http://manuals.heartlandowners.org/manuals/User%20Guides/Water%20Systems%20Guide%20V1.1.pdf

bid_time wrote:
cchristanis wrote:
I read to never leave both grey and black valves open at same time to prevent gas from going back in

wing_zealot wrote:
Don't know where you read such nonsense but think over what you read, some is credible, some not so much.
What it says is to not leave the valve open while camping. It doesn't say anything about having both valves open while dumping.
Cummins12V98
Explorer III
Jun 28, 2015
If your RV has a tank rinse it has a built in back check.

I hook a non drinking hose to the flush. Open the black tank valve let it drain until it runs clear. A clear elbow is needed for this.

At this point I close the black tank valve and set a timer for 6 minutes on my phone and place it in my pocket.

Timer goes off I open valve let it run clear then repeat the 6 minute fill and drain. All the while letting the tank flush run. Close the valve and count to 60 then shot water off to flush. Go inside add chemical to toilet fill bowl with water and flush. Now you are done and following this you will never have the dreaded POOP PYRAMID!

I usually do this the day before we travel so the tank will have something to slosh around while traveling. I also make sure there is water in the grey tank when traveling.
IAMICHABOD
Explorer II
Jun 28, 2015
Very interesting. Happened to Son In Laws trailer when others dumped.

cchristanis wrote:
It was here p.18 under camping with grey valves open section:

http://manuals.heartlandowners.org/manuals/User%20Guides/Water%20Systems%20Guide%20V1.1.pdf

bid_time wrote:
cchristanis wrote:
I read to never leave both grey and black valves open at same time to prevent gas from going back in

wing_zealot wrote:
Don't know where you read such nonsense but think over what you read, some is credible, some not so much.
dave54
Nomad
Jun 28, 2015
I do not flush every time I drain the black, especially when on long trips. Once home I do a thorough rinsing.

I have never 'sanitized'. I do not see the point in that. I am assuming that was simply a poor choice of words by the OP.
cchristanis
Explorer
Jun 28, 2015
It was here p.18 under camping with grey valves open section:

http://manuals.heartlandowners.org/manuals/User%20Guides/Water%20Systems%20Guide%20V1.1.pdf

bid_time wrote:
cchristanis wrote:
I read to never leave both grey and black valves open at same time to prevent gas from going back in

wing_zealot wrote:
Don't know where you read such nonsense but think over what you read, some is credible, some not so much.
lanerd
Explorer II
Jun 27, 2015
Many of us actually use the soapy water from the gray tank to help rinsing out the black tank. Those with macerators can do this simply by shutting off the macerator and opening both gates. For us without macerators, I had to install a third gate to be able to shut off the drain and still open both tank gates.

I usually will drain the black tank and then shut off the third gate and open the gray gate. The soapy water will flow back into the black tank and when the two have equalized, I shut off the gray gate and open the third gate to drain that water out of the black tank. I'll usually do this a couple or three times (depending upon how much water was in the gray tank), until the water coming out of the black tank is clear. During all of this, I will keep the black tank rinse running.

Gas in the tanks??? Who cares? Both tanks are vented out the top of the roof.

Ron
rhagfo
Explorer III
Jun 27, 2015
Lots of good information here and some not so good.
You really don't want to sanitize the Black Tank, you want it do a little digesting of paper and solids.

My procedure is similar to many, just a bit different.
We have three waste tanks Black, Galley, and Grey (Shower & Vanity). I also have a clear 45 degree elbow, to observer the drain process.

First I drain the black tank, once most is drained I then turn on the flusher (Connected with my general use garden hose). Then after a bit I set the timer on my Smart phone for 3 minutes, and Close the black tank valve (CAUTION DO NOT GET DISTRACTED!!!) When time is finished I open the Black tank Valve and let the rest drain out. Then turn off the flusher, and close the black tank valve.

Next, I drain the Galley tank, semi clean water maybe a little greasy and small food particles.

Last I drain the Grey tank, shower water, clean slightly soapy water, this will rinse out the stinky slinky, leaving it clean when disconnecting.

I keep the slinky and all fittings in a Vinyl 5" X 8'fence post under the 5er.
bid_time
Nomad II
Jun 27, 2015
cchristanis wrote:
I read to never leave both grey and black valves open at same time to prevent gas from going back in

wing_zealot wrote:
They're making it way to complicated. Hook up slinky and drain the black tank. While the tank is draining hook up the hose to the black tank flush. When the black tank is done draining, leave the black tank valve open and drain the grey tank. While the grey tank is draining turn on the water to the black tank flush. Flush the black tank for about 2 minutes ±. Turn off the water to the black tank flush and disconnect hose. When both tanks are done draining close both valves, put on the cover, stow slinky, and leave. Total time - less then 10 minutes (probably closer to 7). Total time wasted on nonsense flushing - None. Total time forcing other people to wait in line for your OCD - None.
Let's assume for a second that gas does go back in. So what, it's not getting into the rv because of the p-traps and besides the tanks are vented. Secondly, the second you use either tank you can start to generate gas. So what you going to do, empty the tank every hour so you don't get any gas in them. Don't know where you read such nonsense but think over what you read, some is credible, some not so much.