Using the Black Tank Flush Valve

[sheridany]

A related black tank rinsing question: The consensus I have read is not to drain your black tank until they are at least 3/4 full in order to flush everything out with the force of the water flow.

So what does one do when they use their rv for a weekend and have less than 1/2 tank full?

Do you add more water to raise the black tank level or just drain it as is with a good rinse. I read somewhere that someone wrote to fill the tank higher using the black tank rinse and I am not so sure of that idea.

 

[TJ&LadyDi]

If we find ourselves in the situation you describe, we just dump what's in the tank and do a good clear-water flush. With the new macerator toilets, there's less chance for solids buildup. Trying to put it delicately, black-tank contents are in a slurry consistence rather than clumps and drain more completely.

TJ

 

[Neal]

So what does one do when they use their rv for a weekend and have less than 1/2 tank full?

I'm sure this could warrant better replies ?

 

[Old-RV'er]

All - Everyone is different, but we ran into one Lady who owned the year before us, when we were picking up our new MH last year. She give us good insight into when to flush black tank, she does it every time she dumps. I asked her why, she said it keeps the sensors working better (although they maybe ultrasonic) and it gets rid of all the bad stuff in the tank. So here is how I do it.

Yes, there is a built in anti-syphon valve built in, I put another one (use Y connector, turn off supply to house when flushing).

I have a special hose dedicated to only flush out black tank, it's a coiled green hose. I hook up a anti-syphon valve and then a pressure regulator, then the flush hose. I do this while the black tank is draining.

Once tank is mostly empty, I turn on water supply and start the flushing process. I let this run for 90 seconds to 2 minutes, then close the black tank valve and with watch, time out 90 seconds - to 2 minutes. Once time elapsed I open up black tank drain valve and again let it run for 2 minutes or so. Then repeat the above three times. I have a clear pipe connector at the end of the sewer hose, and once it is running clear (or as clear as this can show) I am finished with the drain/flush process. I shut of flush water supply, it will drain out of the anti-syphon valve for a bit. Then I disconnect the hose from the supply, then take the AS and regulator off the hose bib. I let the green hose drain onto the ground for a bit. Then disconnect the hose from the coach, put the cap back on, and stow my stuff in the rear most drivers side compartment, small enough for not much of stuff, but it holds all this. I am anal, I attach the AS, WP regulator, and connect the male end into the AS so in effect I have a loop of sealed hose. The next time I don't have to look for anything it's all connected together.

As mentioned, I let the tank hit the 3/4 full mark, or the yellow light on the panel inside to light up. It takes a day or so, for anything to show on the tank gauges in our coach, this was true as well for the lady we ran into who advised us to flush every time we dump.

Have Fun!

 

[TJ&LadyDi]

I have a special hose dedicated to only flush out black tank, it's a coiled green hose.

This is a good point. I mark all the hoses I carry in the coach (except the one on the hose reel) with colored electrical tape; green for potable fresh water and red for sewer flush and other non-potable water use. I put a wrap of colored tape on each end of the hose, about 3" back from the connector. That provides a visual identification when hooking up.

TJ

 

[boomer]

Not having two macerator toilets and sensors that have been replace twice I go through a ritualistic exercise when I drain my black tank. At the 3/4 mark I drain like everyone else, turn on the rinse part way through. Run the rinse for 5 minutes after tank is 'empty'. Close the valve, put 30 gallons back in (I have a gauge), dump the tank again (rinse on), repeat the 30 gallons again (sometimes I do 40). Finally close the black tank, open the gray and go inside and pray. Normally the gauge will still read 3/4 tank (love the KIB sensors) until we flush either toilet a few times, then the reading goes to less than 1/4.
Brought this up with Newmar/KIB and they insinuated I wasn't using chemical. After the tank gets to 1/2 I add Aqua Kem every time. Being we are full time I put Tank Blaster in overnight every 1- 1 1/2 months.
Had this issue with black tank since the first 5 months of ownership. Apparently there is just no fix.
One saving grace, once the sensors start reading the tank is near empty, it reads fine.

 

[tgdiebolt]

It seems that this mod will only work with the water pump ON. For city water you would need to add a faucet to the in coming water system. Correct?

 

[AbdRahim]

Here is what I used. One has a slightly different angle (blue) but here are options. I do not use a mixing setup as of yet, haven't had a need.

https://www.amazon.com/gp/product/B00MA9F4XC/?tag=rvf01-20

https://www.amazon.com/gp/product/B000CFJ3WE/?tag=rvf01-20

https://www.amazon.com/gp/product/B00835QF8K/?tag=rvf01-20

The weight of these don't put a strain on your connection? I would love to see pictures of how you place these.