Black Tank Flush Procedure

amanda_h · 05-28-2007, 09:31 AM

Hi again, everybody. Thanks so far for all the responses in the other threads I've posted!

Another newbie question that I know has been talked about before here but the discussions I've found were not real clear.

When hooking the hose to the black tank flush connection, are we supposed to leave the dump valve open during this procedure? It sounds like it.

And then we have the option to close the valve and fill the black tank until we have a few gallons of water in there?

So far what we've been doing is that DH just puts a hose end down the toilet and fills up the black tank that way for rinsing.

He's been using a mixture of Calgon, laundry soap and bleach in a bucket right after dumping but to get enough water back into the black tank, he goes in and out of the motorhome with a bucket of water to throw down the toilet each time. Can he just save those steps by using the "black tank flush" connection to get enough water in the tank after dumping?

I guess he's using the methods of the Geo system but not quite the procedure. *laughs*

Thanks for any clarification.

~~amanda

amanda_h · 05-28-2007, 09:31 AM

Hi again, everybody. Thanks so far for all the responses in the other threads I've posted!

Another newbie question that I know has been talked about before here but the discussions I've found were not real clear.

When hooking the hose to the black tank flush connection, are we supposed to leave the dump valve open during this procedure? It sounds like it.

And then we have the option to close the valve and fill the black tank until we have a few gallons of water in there?

So far what we've been doing is that DH just puts a hose end down the toilet and fills up the black tank that way for rinsing.

He's been using a mixture of Calgon, laundry soap and bleach in a bucket right after dumping but to get enough water back into the black tank, he goes in and out of the motorhome with a bucket of water to throw down the toilet each time. Can he just save those steps by using the "black tank flush" connection to get enough water in the tank after dumping?

I guess he's using the methods of the Geo system but not quite the procedure. *laughs*

Thanks for any clarification.

~~amanda

Hikerdogs · 05-28-2007, 10:04 AM

Using the black tank flushing connection accomplishes the same thing as carrying buckets of water or sticking the hose down the toilet. The upside is that you don't have to take a chance of getting everything in the coach wet.

When we flush our tanks I connect the sewer hose and the water hose to the flush connection. I dump the black tank first, then start the fresh water running through the flush connection. I leave the drain open for about 30 seconds then close it to allow some water to fill the tank. After another 30 seconds or so of running in fresh water I reopen the drain valve to let everything out.

At home I have a clear sewer hose so I repeat the process until only clear water comes through the hose. At the campgrounds I do the process a couple times just to make sure the tank is fairly clean.

If you want to leave some water in the black tank just let the water run through the flush connection for a few seconds with the drain valve closed. We don't add much water to the black tank. just enough to disolve the deodorizing packet.

Once the black tank is clean and the drain valve is closed we empty the grey. Ours doesn't have a flush connection on the grey tank, but I'm thinking of installing one. It's hard to get all the food particles off the sensors and the bottom of the tank without flushing.

mrbojangles · 05-28-2007, 10:20 AM

amanda,
i think "hikerdog" has it pretty much right.
the only thing i do different, is that i will close the black valve for 2-3 minutes and then open again, do this a couple of times. look at black water coming out to see how clear. this seems to work for me.
good luck!!!
mrbojangles

Captain Bud · 05-28-2007, 10:21 AM

You're right on the money Hikerdog with the procedure you have outlined. I have yet to have a problem doing it this way. I would like to add that I add tank treatment to my gray tank about every 3rd dump.

amanda_h · 05-28-2007, 11:03 AM

Thanks so much everybody!!

DH will be glad to hear that he doesn't have to keep lugging buckets of water into the coach!

~~amanda

Fakrwee · 05-28-2007, 04:06 PM

On my last trip I left the water flush open while I broke down camp and was surprised to see how much more was flushed out. I usually leave it open for 10-15 seconds 2 or more times than close it. Last time I left it on for about 10 minutes. Big Difference. Try it once in a while. Happy camping.
Tom

Oh-one · 05-28-2007, 04:40 PM

I put a in-line cutoff valve in the black tank flush fitting on the MH. You can get them at Lowe's for a few $$. I use a separate hose that is colored grey and not a drinking hose for the flush water. I put a "Y" type cutoff valve at the camp water faucet and hook up both white and grey hoses when we arrive. When it comes time to empty the black tank,I turn on the black flush valve and let the fresh water stir up the black tank before I open the black tank dump valve. I continue the black flush for a while after the tank empties. I then close the black dump valve and continue the black rinse for a second flush. After the second flush I close the black dump valve. I allow the tank flush spray to put some clean water in the black tank. After the black tank is completed I open the grey dump valve and use the grey water as a rinse for the sewer hose. When I remove the hose I spray it with clorox bathroom spray and flush with fresh water,using my grey hose. The hose and the tanks are clean and ready to go.

Izzyblueye · 05-29-2007, 03:41 AM

The advice you have been given here is all right on the money. Two cautions I would add are. Don't overdo the chemicals in the black tank. It's the bacteria that makes it work, you don't want to kill them off with chemicals. The other is, if you use a "Y" to run two hoses, be sure you close the valve to the fresh water side before you flush the black tank. Then be sure you close the valve on the black tank hose to prevent back flushing into your fresh water supply hose. It's all very easy otherwise.

skigramp · 05-29-2007, 01:32 PM

I would add 2 comments to this thread ...

1) I suggest you buy a short "clear" expansion to attach to your dump ... they come with male and female bayonet mountings ... leave it permantently attached to the dump ... it serves two purposes ... a) you can see how "clean" the tanks are as you flush ... b) in case that you forget to close the flush valve when you put the cap on it will save you from any surprises the next time you take the cap off ... and please don't ask how I know this ...

2) All of these back flush attachments on Winnebago and Itasca motorhomes have anti-siphon devices in them ... so you will not contaminate your drinking water ...

amanda_h · 05-30-2007, 02:47 PM

Thanks so much for the additional replies!

Oh-one: Why do you have a Y connection out of curiosity? I guess I don't get why you'd want to keep the hose hooked up the the flush valve all the time. Thanks.

Homer: Do you think the solution we described will hurt anything by putting too much in the tank? Again, we put a solution of laundry detergent, Calgon, and bleach. Thanks.

Skipramp: Gee, yeah, I don't want to ask what happened! *cringes* Yeah, we use a clear elbow at the connection but we take it off after dumping. Do you mean to just leave it on and attach the cap to the clear elbow? Thanks.

~~amanda

Izzyblueye · 05-30-2007, 03:15 PM

amanda H: The "y" is used frequently by folks that stay a week or more at one site. It allows them to keep the tank flusher hooked up and the fresh water at the same time(this assumes you have only one water bib available). The "Y" has ball valves built in that allows you to switch back and forth. I personally do not trust the factory vacuum breakers. One failure could make a lot of people very sick.
The detergent will probably not hurt the bacteria action, the bleach will kill bacteria. The calgon will not hurt anything. You really do not need any of these things as long as you fluh well after each dump cycle. I do like to put a little detergent in my black tank with 5 gallons of water on the trip home to clean the inside walls of the tank, not entirely necessary but works well. IMHO

amanda_h · 05-30-2007, 03:56 PM

Hi Homer!

Thanks for your response.

I'm trying to think about what you said. Since you aren't flushing the black tank everyday, why is it necessary to leave the hose hooked up? Why not just connect the flush hose when you need it?

And when you say you don't trust the factory vacuum breakers, can you explain? What are vacuum breakers and where are they and what function are they providing.

I'm sorry. We're just so new at all of this that it's just so overwhelming.

Thanks!

~~amanda

Geechee · 05-30-2007, 04:15 PM

Only one thing I can add, is that there is a check valve in the flush line that will not allow back flow into the fresh water supply line. How do I know you ask. Well when we first purchased our brave I hooked up the hose to the flush connection and nothing happen except for a pressure build up in the water hose. At the first repair trip the dealer found that the check valve was installed backassward at the factory. After the alignment was corrected it worked great. I also noticed that after shutting off the water there was always a flow of clear water out of the connection when the hose was disconnected.

Izzyblueye · 05-30-2007, 05:05 PM

The only reason to leave the hose hooked up for the tank flusher is convienance. Vacuum breakers or check valves are just terms for relieving the water pressure that builds up between the flush valve inlet on the tank and the hose/water bib or faucet. If you want to hook and un-hook each time you flush there is certainly nothing wrong with that. Some c/g's have twin bibs making it even simpler. Hope this helps, all of us are here to help one another.

skigramp · 05-30-2007, 05:23 PM

Yes I leave the clear elbow on all the time ... it is "geezer" protection ... in case you put the cap back on and forget to close the valve ...

I put the cap on "below" the clear elbow ...

amanda_h · 05-30-2007, 05:55 PM

ok, I thiiiiiink I understand what's going on.

Geechee: Thanks for explaining that. Makes good sense.

Homer: Convenience! K, got it! Thank you so much! I thought you may have been talking about those "valve dump handles" that are used to open the tanks. I thought maybe they are on a vacuum system or something. I mean, they're kind of SCARY! Why? ...because there's not a detent on those handles to make if feel like they're closed. Just kind of a mushy action as you pull in and out on the handle. Why don't they make a "click" sound or feel so we can be more assured that the valve is closed. It seems scary in that it almost feels like they can work themselves open. I don't get it ...why were they engineered like that? That doesn't bother anybody???

skigramp (sorry I misspelled your name in the last post!): Thank you for clarifying that. Good idea, I don't know why we are taking it off and keeping it with the hose. It makes more sense leaving and put the cap on it. thanks!

Oh-one · 05-31-2007, 12:05 PM

I am sorry for a late reply to your question of why I leave the "Y" hooked up and both hoses in place. It is for my convenience, since I have often had to perform the tank flush in very cold ,rainy weather and often after dark. It saves me time outside and makes the job faster and easier. You can do as you please with the flush hose, I just want to get it over with as quickly as possible.

amanda_h · 05-31-2007, 02:48 PM

Thanks, Oh-one, for getting back to us! ...makes perfect sense now.

~~amanda