Flush King verses built-in hose mounted black tank flush system

PT RV`er · 06-09-2014, 03:59 AM

Well after reading the post " stinky toilet " I decided to try a test between the two black tank flush systems. After this past use of the rig, I hooked up to the built in black tank flush system and let it run for at least 15 minutes. I looked at the drain pipe end as it flowed into my city sewer connection to see if waste was coming out during the wash. There was some waste coming out with the water. So I thought this built in system works well.
This is what I used since I bought my rig new last year and I thought I was doing good. After using this method, I too had a hint of sewer smell in the rig after it sat up for a bit.
So, I then hooked up my Flush King that I`ve had and used on my previous rig. Boy I was surprised. The amount of waste and solids that came out after using this system was like I didn`t even flush the tank out. Now I know why I kept having a sewer smell. It took 2 flushes with the Flush King and then I had clear water coming out of my tank. The Flush King is a clear plastic attachment so you can see whats coming out of your tank.
So the built in system works to an extent, but it really doesn`t clean the tank out like you would hope. I just wanted to post my findings after I read about the stinky toilet. I hope this info helps out a few people with their odor problems. I know it helped me out. I will now use my Flush King every time like I did on my old rig.
Here`s to an odor free rig.

hankaye · 06-09-2014, 06:10 AM

PT RV`er, Howdy;

I'm sure that the Flush King works well when there are a minimum
of turns a relatively straight shot to the tank. On others, such as
my system, there are two 90* turns and an up hill run to deplete all
the force from the jet of water. When I'm finished with the flushing I
I do the Downey routine then take Rascal for a run while the fumes
dissipate, no fuss ... no worries ... no aggravation ... be happy.

hankaye

{tpc} · 06-10-2014, 04:51 AM

Quote:

Originally Posted by PT RV`er

Well after reading the post " stinky toilet " I decided to try a test between the two black tank flush systems. After this past use of the rig, I hooked up to the built in black tank flush system and let it run for at least 15 minutes. I looked at the drain pipe end as it flowed into my city sewer connection to see if waste was coming out during the wash. There was some waste coming out with the water. So I thought this built in system works well.
This is what I used since I bought my rig new last year and I thought I was doing good. After using this method, I too had a hint of sewer smell in the rig after it sat up for a bit.
So, I then hooked up my Flush King that I`ve had and used on my previous rig. Boy I was surprised. The amount of waste and solids that came out after using this system was like I didn`t even flush the tank out. Now I know why I kept having a sewer smell. It took 2 flushes with the Flush King and then I had clear water coming out of my tank. The Flush King is a clear plastic attachment so you can see whats coming out of your tank.
So the built in system works to an extent, but it really doesn`t clean the tank out like you would hope. I just wanted to post my findings after I read about the stinky toilet. I hope this info helps out a few people with their odor problems. I know it helped me out. I will now use my Flush King every time like I did on my old rig.
Here`s to an odor free rig.

I have a question. Do you have a straight shot into the tank for the flush king, or do you have some (what I remember as) 45 degree angles where the gray and black tanks connect to one pipe?

I don't have a flush king but I do have a camco dual flush, though I have yet to use it. I have used the blank tank flush on the back of the trailer which seems to work ok, well at least I can see more coming out. I'm just wondering how well if at all my camco or a flush king will work?

As near as I can figure out I think there is only one bend going back into the black and gray tanks. But the bottom is enclosed so that is tough to really figure out.

PT RV`er · 06-10-2014, 10:08 AM

This is what I have coming out from under my rig. I poked around and found out that I have one 45 degree angle that I can tell. On my old rig I had two 45 degree angles and it still worked great. All I was doing is posting my results from my own test. Whether it will work on your rig or anybody else's, I can`t tell you. But from my experience so far, the built in system does an O.K. job, but not the best it can be. I even flush my gray tank, even with the 1 inch line and it still works.

{tpc} · 06-10-2014, 12:32 PM

Ok thanks for the info. Mine is a little different, has like a "y" pipe where black and gray both meet and join as one.

I probably just need to play around with the camco I have a little more and figure it out. Just one of those things that can be hard to do when trying to leave the campground.

Javi · 06-10-2014, 01:00 PM

I suspect that the reason the flush king works better than the built in flush has more to do with the volume than anything. The flush king pumps water back through the drain line until you close the valve, usually when you think the tank is pretty much full. Then you open the drain and let the water out.

Do the same with the built in flush and I'd bet it will show the same results.

I have and use a flush king, I do not have the built in on my present trailer. However, I have also simply filled the tank with the foot valve on the toilet and experienced similar results when repeated an equal number of repetitions

Sent from my GT-P5210 using Tapatalk

tech740 · 07-06-2014, 02:09 PM

I have the buit in on our 2920bh and I use it and let it run for about 5 minutes. Then I use it to fill the tanks as Javi has said. I do that three or four times. No odor as of yet. Seems to work great.

**chuckster57** · 07-06-2014, 02:24 PM

I use a piece of clear attached to the trailer and the sewer hose attached to that. Then I just use the black tank rinser built into the trailer. Close the drain valve for a few minutes and then look at the water when I open it up. Dirty? Do it again. My '97 Jayco didn't have a rinser, so I'm lovin it in my Copper Canyon.

**JRTJH** · 07-06-2014, 05:28 PM

If you go to a quarter car wash and put 75 cents in the coin slot, the high pressure water starts flowing. Walk to the front of your truck and spray the grill well, then walk to the tail gate, you'll still have dirt on it. Now, walk to the driver's side and spray well, walk back to the tail gate and it will still be dirty. Now walk to the passenger's side and spray till the time runs out. Walk back to the tail gate: Yup, still dirty......

When you use the "permanently mounted" black tank rinse, you'll be spraying all sides, top and bottom EXCEPT the tank wall the fixture is mounted on. Use another angle and spray water, you'll get "all but the side the spray is attached to.

The only really good way to rinse the inside of the tank is to repeatedly fill and empty it. No single appliance will reach all sides, top and bottom of the tank from one location, so it stands to reason that the Flush King will do a better wash on the tank wall where the built in rinse is installed. Of course that depends on whether or not the spray will even get to the tank with any force depending on the number of turns and the distance of the plumbing run.

No one method will spray all of the inside of the tank and effectively clean it any more than standing in one place in a car wash will clean your entire truck. That's why most of us, over the years have come to the conclusion that simply filling and emptying the tank a number of times is the best way to get as much of the solid residue as possible out of the tank. Even then, I'm not inclined to open the valve and take a good "whiff".... There's still going to be some residual "stink" no matter how well you flush the tank. That's why we add Downey, Calgon or a tank deodorant after it's empty, flushed and the valve closed.

tech740 · 07-06-2014, 05:38 PM

Mine has multiple heads inside not just one spray nozzle. When I asked I was told it hits all the angles in the tank. Totaling 6 or 8 nozzles.

**JRTJH** · 07-06-2014, 06:31 PM

Quote:

Originally Posted by tech740

Mine has multiple heads inside not just one spray nozzle. When I asked I was told it hits all the angles in the tank. Totaling 6 or 8 nozzles.

Whatever you have is not what is in the Keystone standard build. There aren't 6 or 8 nozzles in even the biggest, most expensive motor homes.

There is one nozzle (see picture) and it has 6 or 8 HOLES, but as you can see, the water spray pattern is pretty well insufficient to clean the black tank. I've also included a typical black tank shape. It's fairly obvious that 40 PSI of water flowing through a nozzle mounted in one wall of a shallow wide tank won't hit all sides.