Lazy Daze Owners' Group

Clean dump??

September 24, 2024, 11:55:58 am

Hi all—New to us, 2007 23 1/2’ Twin-King.   Having trouble getting a clean/complete dump on the black tank.   Don’t know what procedure the former owner followed, but the tank will not drain completely and there is always water and debris left after the dump.   The dump itself is not forceful but slowly runs out.  I have flushed and flushed the tank using a garden hose with a pressure nozzle, but it still stays the same.   Put my hand up the dump valve and was able to dislodge several large (2x2”) pieces of calcium/mineral deposits.   The throat of the dump valve/tank still seems to have rough pieces of deposits around the opening.  Does anyone have any good suggestions as to how to dissolve whatever is on the bottom of the tank that is keeping me from achieving a clean dump?   I was thinking on the lines of a bottle of CLR or LimeAway and letting it sit for a while to try and dissolve whatever is there, but I hesitate because I think it might damage the tank?   Any help would be appreciated!

Re: Clean dump??

Reply #2 – September 24, 2024, 02:15:26 pm

" Does anyone have any good suggestions as to how to dissolve whatever is on the bottom of the tank..."

Have you ever had any experience with the old fashion 'Outhouse', aka Privy ? What goes in, stays in... and over time solidifies into something like concrete! If you connect your dump hose to a sewer receptacle and leave the dump valve open all of the water (liquid) will drain away. What you are left with is a Privy on wheels! Those turds are going to sit there and solidify.
I believe that is the cause of your present problem.

You MUST always keep a fair amount of water in the black tank so the effluent will not harden. and, as Larry points out, enzymes are the best solution (pun intended!).    

Re: Clean dump??

Reply #4 – September 24, 2024, 03:37:53 pm

Hi Chartrue2;  I also have a T/K, older with a separate black and gray dump valve. I don't remember if your '07 has combined plumbing.  When my tank is empty and clean I can see through the toilet to the ground if my sliding gate valve is open.  You should be able to remove the four bolts holding the valve on. My valve comes straight down, no angle or other fitting. So you might be able to see anything in the way better. (I put in stainless screws and nylock nuts adjusted for just the right tension, to not leak, but easier to open and close the valves.)
   I did clean out a black tank drain issue on a friends 2001 MB that he(we) had just bought, and a tangle of hair had been flushed by previous owners teen age daughter(?), over time and had accumulated and caught on the inside, near the gate valve, slowing down emptying flow. I since heard that this is a 'common practice' with residential toilets from a plumber friend. We pulled out quite a bit! Chemicals didn't seem to have affected the hair much, if at all. The MB has a more convoluted drain system than the T/K. Good luck, let us know when you find the issue.
   K2R or lime away dissolving hard water deposits may be the answer for this tank. It shouldn't harm the tank or stainless parts of the valve.   RonB