Proper procedure for black tank rinse/sanitize

While waiting for the black tank to drain, I use the hot water from the water heater (keep it hot till then) into a home depot bucket. I then prop the flush handle open on the toilet and pour 4 gallons of hot water right down the toilet hole in about 6 seconds like a power flush. I do that twice then shut the flush handle and the black drain handle......then open the grey tank.

Our black tank flush was installed at the factory with a back flow preventer pre-installed. Our toilet sits directly above the black tank and the flush is just below the bottom of the toilet. I don't really think it would be possible for contaminated liquid to flow back into the flush outlet unless the water level was above the outlet.

Like Dennis (Executive), we usually leave the grey tank valve open all the time, until the day before we expect to empty the black tank. That way the grey water can rinse the sewer hose. Unlike Dennis, I let the black tank fill pretty full. I can tell by the sound of the black tank flush when the tank is almost full. Once I hear the change in the sound, I open the black tank valve. Depending on the water pressure at the park, it may take 5 to 10 minutes to fill. Just don't walk away and forget about it.

Our black tank flush sends water in all different directions, but I don't think it is enough to really rinse the tank. That is why I like to fill it up and then dump it again. The suction created by the water rushing out of the tank helps pull solids out of the tank. I usually rinse the tank 3 times until the water runs clear. You can get a clear sewer hose extension that is straight, with a 45 degree elbow or a 90 degree elbow to keep an eye on what is coming out of the black tank. I don't use any chemicals or enzymes in our black tank and don't have odor in the camper.

After the black tank is fully rinsed to my satisfaction, I put a few gallons of water back into the tank before turning off the supply to the black tank flush. I do use a grey water hose that is grey and is stored separately from the fresh water tank.

-Michael

I would like to add - - I ALWAYS use a completely different hose for my black tank flush... And it is also black , so there is no confusing it for the white/potable water hose..

See my comment in RED below.

cchristanis wrote:
Hi all. i have one of those rinse/sanitize(it does not 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? (Yes, you need this)It cant get back into your faucet , can it? (Yes, it can)
Also, do you leave the gate valve open on the black tank the whole time? (Never, never, leave the black tank valve open. Without water in the black tank, poop will pile up when it falls into the tank, causing what's known as a poop pyramid.)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).(Typically, the rinser is a "spray" device that sprays to different parts of the black tank.) Thanks a lot

The procedure, as others have described, is simple. Keep the black tank valve closed, use plenty of water before, during and after draining, and wait until the tank is about 2/3rds full before draining. During draining use the rinse (as described by others above) extensively.

I might add to the importance that after draining, you must ALWAYS put more water back into the tank to insure the poop does not solidify and it enhances the dissolving of the solids, toilet paper and promotes better gravity flow when draining. Very, very important.

Many people use chemicals to help with odor and dissolving. Personally, I have only used water in all my years of owning an rv. In my opinion, chemicals are a total waste of $$. If you have an odor, you have a problem that should be fixed....not covered up and if you use plenty of water, dissolving and flow will be taken care of.

Hope this helps

Ron

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

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.

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

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.

Rinse? Yes. Sanitize? No way.