Black tank flush - backflow again

[MORobb]

Hello All,

My black tank flush must have the valve stopped up. I have seen some links on the forum to a brass replacement, but can not find it again. If anyone has the link to get a replacement I would appreciate it if you would post it!

TIA

MORobb

[DQDick]

Most of the folks who replaced the inside one got the replacement at Lowes or Home Depot or someone like that. Those of us who just eliminated it using shark bites and use an outdoor one get them at the same place or at most hardware stores. I got mine from Amazon, it's the backflow preventor that restaurants are required to have on mop sinks or outdoor faucets.

[RMcNeal]

I simply eliminated ours using sharkbites as Dick stated, then put this on the inlet in the convenience center from Amazon
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[psomers]

Wouldn't a back flow preventer in the convenience center cause a retention of water in the line from convenience up to the high point where the vacuum breaker was? How do you get that water out to prevent freezing?

[RMcNeal]

When I winterize, I typically just use air to blow out the lines, so anything in that line gets blown into the black tank. I suppose if you winterize with the pink stuff, you could do that as well, but since I live in Florida, the "blow it out with air" system works fine for me. Very little threat of a hard freeze to bust a line.

[BB_TX]

If you use the pink stuff to winterize, you can pump antifreeze thru your outside shower and then connect that shower hose to the black tank flush connection and run some pink stuff thru it. That is what I do.

[BB_TX]

Originally Posted by MORobb

Hello All,

My black tank flush must have the valve stopped up. I have seen some links on the forum to a brass replacement, but can not find it again. If anyone has the link to get a replacement I would appreciate it if you would post it!

TIA

MORobb

Does your flush connection have a check valve at the hose connection? If so, it may be stuck closed.

[wed]

Yep DQDick is right.

[MORobb]

thanks for the replies. I think I will remove the one under the sink.

MORobb

[Rdt1012@att.net]

Lowe’s. Cash Acme antisiphon vacuum breaker

[VagabondLove]

Ours clogged a few years ago, and I decided to change my approach. Given how slowly the flush system filled the tank (30 minutes?), there really is probably only a sprinkle going into the tank...not enough to loosen up deposits.

Now I just bring the 2nd water hose into the bathroom from outside and stick it down into the toilet an inch or so, letting that full blast of water do it’s magic. Let it run until the effluent is clear, then close waste gate and fill tank in 5 minutes, open waste gate and see all that you freed with those strong hose currents. Repeat.

When traveling, we keep all tanks half full with clean water and let the sloshing loosen everything up, then dump when we arrive. I saw someone mentioned adding dishwasher detergent to clean the tank and get those sensors working again. We are going to try that Sunday when we start up this year’s trip around America after being stationary for 5 months. I will let you know how the Cascade works.