Black water flush hose

[MikeFromMesa1]

Our new RV has a black water flush connection, something we have never had before on an RV, and I am trying to figure out how best to use it. We have been typically dumping at a dump station, not at a site, and have never seen a hose connection at a dump station without an attached hose. Typically we had just used the attached water hose to fill a container to refill the black water tank after dumping, and then dump a second time.

Is it best to use a different hose for flushing? My mind tells me that only clean water moves through the hose and I should not be worried, but I cringe at the idea of hooking a fresh water hose up to flush a black water tank and was planning to buy a second hose just for that purpose. Is that silly?

Is the flush typically used at the site? Or at dump stations? As I mentioned I have never actually seen a regular hose connection at a dump station without an attached hose and would not think that the park would want me disconnecting their hose from their water pipes, but understand that I might be completely wrong about that.

How long should fresh water be put through the black water tank? A couple of seconds? A minute? More? I want a clean tank, but I do not want to waste water and fill up a septic tank for no good reason.

Any help would be appreciated.

 

[Jimdamedic]

I do not use the flush system at a dump site if people are waiting. If they aren?t, I?ll go ahead and use it. If I dump at a campsite I use a different hose.

 

[Hammster]

That tank flush system is the best thing ever for black tank maintenance. We use ours every time we dump. It helps keep the tank level indicators working accurately as well as flushing the tank.

Here's how I use it. After dumping the black tank, I close the tank dump valve and connect a hose that is not my drinking water hose to the flush. I leave the tank's dump valve closed and I start the flush and watch the tank level indicators until the tank reads at least 2/3 full. If the full light flickers, even better. Turn off the water to the flush and dump that load of water. If I'm dumping at my site I'll do that a second time. If I'm at the dump station, I'll just do it once so people don't have to wait too long. You kind of get a sense for how much time it takes to get the tank to 2/3 - full but be sure to check the tank level indicators just to be sure. After the last flush, we add 2 oz of chemical to the tank and some amount of water. We do that through the toilet.

Hose use. Do not use your potable water hose for the tank flush. Keep a separate hose for that. Part of the reason is usually the water at the dump stations is not potable water so you don't want to run it through your potable water hose. Another reason is you could get a back flush into the hose from the tank flush. Not likely, but not worth the risk. Keep potable hose and flush hose completely separate.

 

[MikeFromMesa1]

That tank flush system is the best thing ever for black tank maintenance. We use ours every time we dump. It helps keep the tank level indicators working accurately as well as flushing the tank.

Here's how I use it. After dumping the black tank, I close the tank dump valve and connect a hose that is not my drinking water hose to the flush. I leave the tank's dump valve closed and I start the flush and watch the tank level indicators until the tank reads at least 2/3 full. If the full light flickers, even better. Turn off the water to the flush and dump that load of water. If I'm dumping at my site I'll do that a second time. If I'm at the dump station, I'll just do it once so people don't have to wait too long. You kind of get a sense for how much time it takes to get the tank to 2/3 - full but be sure to check the tank level indicators just to be sure. After the last flush, we add 2 oz of chemical to the tank and some amount of water. We do that through the toilet.

Hose use. Do not use your potable water hose for the tank flush. Keep a separate hose for that. Part of the reason is usually the water at the dump stations is not potable water so you don't want to run it through your potable water hose. Another reason is you could get a back flush into the hose from the tank flush. Not likely, but not worth the risk. Keep potable hose and flush hose completely separate.

Thank you. That validates the part of me that kept telling the rest of me to use a separate hose, not the potable water hose. We do not drink from our fresh water tank, but we do use it for washing and I thought using the same hose for both purposes was just begging for trouble.

 

[steveblonde]

I never do it at the dump station because i have a 40gallon black tank it takes a good 15 mins to fill and flush ,i do when i have full hook ups once or twice a year thats it, i also dont need another hose that way either, and there is no pressure to rush it, i have a beer

 

[Rene T]

Thank you. That validates the part of me that kept telling the rest of me to use a separate hose, not the potable water hose. We do not drink from our fresh water tank, but we do use it for washing and I thought using the same hose for both purposes was just begging for trouble.

Also, I wouldn't want to hook up my potable water hose to a CG valve without knowing how the last guy used it. It may be covered with you know what.

 

[ArdraF]

I wouldn't want to hook up my potable water hose to a CG valve without knowing how the last guy used it.

Re fresh water.  Jerry always sprays and/or washes a campground spigot with Lysol before attaching our potable water hose.  We also have various filters starting at the campground spigot.  We use our onboard water for drinking, washing dishes, etc. and have never had a problem.  He also uses regular Clorox (no additives) in the fresh water tank to kill anything that might get in it.  The onboard water tank is meant to be used so you can use it by taking the proper safety precautions.

As to the black water flushing, many people do not have a flushing mechanism.  They simply drain the black tank first, then the gray tank which washes out the large hose.  This is good enough if there's a line waiting and you want to hurry.  You can always flush the next time you dump.

Just always keep your potable water hose separate from all the sewer stuff.

ArdraF

 

[HappyWanderer1]

I carry two 10-foot hoses for draining gray water and flushing at the dump station. They're gray, so it's easy to remember what they're used for!

To flush: after the black tank stops draining, I'll turn on the line to flush the tank. When it runs clear, I'll close the black tank valve for a couple of minutes, then open it again. I'll do that a few times until nothing is visible in the clear elbow on the sewer hose. Gray water is then dumped to flush out the sewer hose.

If there's a line at the dump station, I'll do an abbreviated version of the above.

 

[MikeFromMesa1]

Also, I wouldn't want to hook up my potable water hose to a CG valve without knowing how the last guy used it. It may be covered with you know what.

Until we bought our new RV I did not even know there was anything like a black water flush valve so it never occurred to me to be concerned about hooking up fresh water at the campground but when I learned of the flush ability during our RV search the first thought I had was "Oh, how nice", but the second thought I had was "OMG. Who knows what was hooked to the fresh water spigot right before we got here". This means that I will now treat all campground water spigots as potentially contaminated and be very careful before I hook a hose to them.

In the past we have seldom actually used campground water. We used to fill our fresh water tank at home and just use that water on our trip unless it got really low. Now we have an actual usable shower in our RV so I am likely to hook up to city water, but not until I clean the campground spigot, and I am not sure what is the best way to do that. Perhaps a bowl of Clorox and water to soak the spigot in, and then wash it with fresh water before hooking up.

You really can't be too careful.

 

[Rene T]

Until we bought our new RV I did not even know there was anything like a black water flush valve so it never occurred to me to be concerned about hooking up fresh water at the campground but when I learned of the flush ability during our RV search the first thought I had was "Oh, how nice", but the second thought I had was "OMG. Who knows what was hooked to the fresh water spigot right before we got here". This means that I will now treat all campground water spigots as potentially contaminated and be very careful before I hook a hose to them.

In the past we have seldom actually used campground water. We used to fill our fresh water tank at home and just use that water on our trip unless it got really low. Now we have an actual usable shower in our RV so I am likely to hook up to city water, but not until I clean the campground spigot, and I am not sure what is the best way to do that. Perhaps a bowl of Clorox and water to soak the spigot in, and then wash it with fresh water before hooking up.

You really can't be too careful.

Just a mixture of Chlorine and water and use a spray bottle.

 

[Gary RV_Wizard]

There is no need to completely fill the black tank & dump again to flush it.  Obviously more rinsing is better, but a short rinse after the first dump should be sufficient for all but the worst case residue.  I'd just give it a minute or two.

The hoses at the dump station typically do not have female hose connectors on the end so as to prevent people from filling their fresh tank there. Most local health codes disallow any fresh (potable) water connection adjacent to a sewer line, so removing the hose connection is a way to show that the rinse hose is NOT in use for potable water.

If the dump station has no available hose connection, simply do as you did before you had a flush inlet.

 

[steveblonde]

My saniflush port is just another hookup along with the city and tank hookups all together with the
Valves and the cable etc etc all together on one central docking station - no need for extra hoses its also a one way valve

 

[ArdraF]

To add to what Gary said, most campground dump stations have the hose for dumping separated by some distance from the fresh water hose so you can't mix them by mistake.  I imagine there's some kind of standard they have to follow because it's so common.

ArdraF

 

[grashley]

My method is slightly different.

I drain the black tank. Close valve
I use the outside shower - converted to hose end - to connect to the flush.  There IS a check valve in the line.  I use water from the fresh tank and the on board pump.  No need to connect to anything at the dump site.  I never use this hose for potable water.

I add 2 - 3 minutes of water to the black tank, then dump.  I repeat two or three times until the water is basically clear.
I add 2 - 3 min of water, turn off the water and disconnect the flush hose, and proceed with gray tank flush.