Using the Black Tank Flush Valve

[FL-JOE]

Each time I empty my black tank I let the internal rinse run with the gate valve open for a minute or so. Then I close the gate valve for 2 minutes, open/empty, and repeat. After these two fills and flushes I generally see clear water coming out.

With my gray I make sure I have 5 to 10 gallons of water in it on travel days. I add one or two pods of Oxy-Kem. It is amazing how much "stuff" will come out of the gray tank and how discolored the water will be when I empty it. During times when we are stationary I will close the gray every couple of weeks and add Oxy-Kem, let it sit for at least 12 hours and then empty.

We have found that odors can come from a gray tank just as fast as a black tank if not kept clean.

 

[Hawkeye]

I flush my black every time I dump. I did the boiler valve mod on the outside shower valves, it's super easy to do. Then put brass quick connects on the boiler valves and the black flush connection. I keep a 3' hose to use to flush, just long enough to hang down below the wet bay door to remind me to shut it off when done because the door won't close with the hose hanging down below the opening a little. I like to use hot water, but it probably doesn't matter.

 

[Neal]

I flush my black every time I dump. I did the boiler valve mod on the outside shower valves, it's super easy to do. Then put brass quick connects on the boiler valves and the black flush connection. I keep a 3' hose to use to flush, just long enough to hang down below the wet bay door to remind me to shut it off when done because the door won't close with the hose hanging down below the opening a little. I like to use hot water, but it probably doesn't matter.

This is ABSOLUTELY the key to black rinse in my opinion. When you can make the process convenient then you'll do it. I keep a flexible hose connected to the "spigot" type connections (aka boiler valves) which give better water pressure and I use a quick disconnect that remains connected to the black rinse fitting. This has been the answer to my laziness and therefore I black rinse nearly every black tank empty now.

 

[TJ&LadyDi]

I did the boiler valve mod on the outside shower valves, it's super easy to do.

I need to get busy and do this too. Haven't found exactly the right valve set yet. I'd like a mixing valve setup with hose connection rather than two separate valves. What did you use @Hawkeye?

TJ

 

[Neal]

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.

Midline Valve 6834 Boiler Drain Valve with Stuffing Box 1/2 in. MIP Inlet x 3/4 in. MHT Outlet, Brass, Lead Free - - Amazon.com

Midline Valve 6834 Boiler Drain Valve with Stuffing Box 1/2 in. MIP Inlet x 3/4 in. MHT Outlet, Brass, Lead Free - - Amazon.com

www.amazon.com

Mueller 102-703 1/2" BOILER DRAIN - Bathroom Sink And Tub Drain Strainers - Amazon.com

Mueller 102-703 1/2" BOILER DRAIN - Bathroom Sink And Tub Drain Strainers - Amazon.com

www.amazon.com

Amazon.com

 

[Hawkeye]

Hi Jim, I did Dutchstar Don's method and went to Lowes and got boiler valves. I don't have pictures, but I'm sure Don does. They are quarter turn 1/2" valves with screw flanges. It's basically plug and play, remove the existing faucet and the pex nut will screw right on to the new valves. I put small stove bolts thru the brass flange to secure them to the existing plastic base plate. The only thing I haven't done yet is to get a short Y to mix water, but at this point I have just been using one or the other and have quick connects on both. I purposely have a longer hose like I explained above, so I don't leave it hooked up or forget it on. This is a 20 minute mod, once you have the parts. Good Luck!

 

[Joe Hogan]

We "flush" the black tank at least once a week when on the road, if able. I am amazed at the amount of solids that are flushed out. Not sure where this stuff accumulates but flushing especially before storage is in my opinion a good idea. Also, I keep some "clean" water in the tanks during storage to keep any residual from drying out. Luckily the storage facility we use has a dump station with water available to flush tanks.

 

[Joe Hogan]

Any links for "Oxy-Chem" pods?

 

[Joe Hogan]

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.

Midline Valve 6834 Boiler Drain Valve with Stuffing Box 1/2 in. MIP Inlet x 3/4 in. MHT Outlet, Brass, Lead Free - - Amazon.com

Midline Valve 6834 Boiler Drain Valve with Stuffing Box 1/2 in. MIP Inlet x 3/4 in. MHT Outlet, Brass, Lead Free - - Amazon.com

www.amazon.com

Mueller 102-703 1/2" BOILER DRAIN - Bathroom Sink And Tub Drain Strainers - Amazon.com

Mueller 102-703 1/2" BOILER DRAIN - Bathroom Sink And Tub Drain Strainers - Amazon.com

www.amazon.com

Amazon.com

How do you attach these valves to the existing plumbing behind the existing mixer?

 

[Neal]

How do you attach these valves to the existing plumbing behind the existing mixer?

Take your wet bay shower panel off. You'll see two twist on connectors on the back. One should be marked with red tape or something, the hot line. Easiest mod you'll do.