Black tank not draining!

I'd try a snake and then driving with some radical turns, starts and stops. Make sure there is water in the tank.

I think more info is needed. When you say you flush the toilet and it looks full, how do you know? Is it not flushing? Can you see it's actually full, visually? What do your tank levels read? Have you let the black tank fill completely before dumping? (this is the recommend method) What is a "blue pack"? And lastly, are you pulling the correct valve?

If when you use the toilet, the drain appears full and when you open the sewer valve the flow is "solid-less" water, yep, the clog is between the toilet and the holding tank.

You can add some commercial dissolver (RV tabs take too long) along with enough water to get it flowing through to the clog or use a mechanical device to break through the clog.

Two words. Poop Pyramid. A snake. A stick. Anything you can get in there from the top or bottom to break up the pile.

After you get it draining nothing is needed except more water when it used and more water when you drain it.

After you resolve your issue and get the tank flowing again, make sure you keep the black water valve closed, and allow the tank to get at least 3/4's full before you drain. Using an application of Happy Camper will go along way to eliminating odors and keeping things fluid. Anyone who tells you that some sort of black tank treatment isnt needed is just plain wrong.
Been MHing 25 years plus, black tank odor and issue free!

IB853347201 wrote:
After you resolve your issue and get the tank flowing again, make sure you keep the black water valve closed, and allow the tank to get at least 3/4's full before you drain. Using an application of Happy Camper will go along way to eliminating odors and keeping things fluid. Anyone who tells you that some sort of black tank treatment isnt needed is just plain wrong.
Been MHing 25 years plus, black tank odor and issue free!

Here we go....:S

Before we learned the proper way to use the black tank, I bought a flusher at Camping World that you used from the toilet. It's only a short stiff hose with and open/close valve and a spray head. It worked well; then we never needed it again. You could also fill the black tank with clean water and let it sit for a while.

Ahhh, yes, you have come across 'Poo mountain'. :)

Happens when too much 'solid' is pushed into black tank and not enough liquid, resulting in said 'solids' piling up and blocking things up in the tank. Typically, the blockage takes the form of a mountain of poo right where it dumps into the black tank from the toilet. Hence the name, 'Poo mountain'.

Just had a visit to Poo mountain last month myself when we were camping at the beach. Was first time in 22 years of RVing that I had such happen. Ended up having to find a pole/stick (old squeegee handle no longer needed) to 'sacrifice' and use to poke down in the toilet, to stir up and break down Poo mountain to get things flowing again. Stir/push some, pour a bunch of water through, then stir some more, more water....Did that a couple times, and eventually poo mountain 'collapsed', and dumped on out.

To prevent that in the future, encourage those that use your facility that when dumping 'solids', Please make sure you run plenty of water through as well. I had to re-educate my gang on such after that incident, haha. :)

Plenty of water is all you need. If your toilet is operating properly, nothing else is needed except maybe a little calgon bath oil beads to help things slide out better. No additive needed at home, same in the RV.