Black tank flush

When I try to flush out the black tank nothing goes in. Not sure if it is the valve or the spray unit is clogged some how. The grey tank flush works fine. Is there an easy fix? Of course, I know the term easy fix and RV do not go together often or well.
Please help.

GARMP, that's an interesting question.


Here are my thoughts.
1. The flush water line to the black tank could be clogged or kinked. If my memory is right, mine is reinforced vinyl hose. It is screwed on to the black tank flush valve and I can see it all the way to the side of the black tank. I'm sure every PC model is different, but hopefully yours is similar. Being that it is flexible you could lie under the RV and trace the hose end to end. If no crimp kinks are visible, you might need to disconnect it from both ends and verify that it is not clogged.  You might even be able to see through it... I think mine is somewhat clear. You might be able to see water, bubbles or the clog.


2. The valve for the black tank could be clogged... While you have the hose off see if water passes thru it.


3. The spinner nozzle inside your black tank is clogged...   That would be the worst case. If it is, then it might be clogged inside the nozzle, or it could be covered with solids inside the tank.  This is going to require cleaning the tank or possibly replacing the nozzle.


Maybe other forum members have some alternate theories. For your sake I hope it turns out to be the 1st or 2nd situation.


Larry

If in a place where this is feasible, I would try this.

- Fill the black tank half way using a garden hose down the toilet.  Nearly hot water is ideal.
- Pour in a gallon of household bleach
- Continue filling with very warm water until the tank is top'd off as seen looking into the toilet
- Let it sit for an hour to loosen crud
- Drain the tank
- Try the tank flush feature
- Good or bad results, either way, you still want to flush out all the bleach residue to protect your gaskets and such, so fill the tank to the top a second time with warm water, let sit for 15 minutes, then drain.

The very warm bleach water could loosen a whole lot of surprise waste so be prepared for the possibility.

I do this with my entire system at the end of our RVing season, gray and black tanks, macerator and all, but I use one gallon of bleach to cover everything.  It keeps everything clean and fresh smelling, something we cannot tollerate given that we sleep above the garage where the motorhome is stored.  We have been doing this since 2007 with no issues with our 2007 PC-2350.

I like to follow Ron's black tank cleaning routine, and rotate between bleach, Dawn dish soap and an enzyme tank cleaner. I figure one of them will attack what the other one does not.   My deviation is that while I have the tank about half to two thirds full, I go for a 30 minute drive. I take a route with lots of turns and bumps to shake it up. That adds some kenetic energy in the tank. That sloshing can really loosen stuff up.


Sometimes I do this routine the day I am headed out on a trip to a park that's close to home.  Then just dump it out on arrival.


My PC is now 15 years old...  Got Clean tanks and the flush nozzles work like new.


Larry

We are going to try the Dawn technique when on the road, as we have no place near here to dump. How much Dawn would you suggest for 25.5 gallon tank?

I'd say about a quarter to a third cup in 25 gallons should be good.  If you put too much in you'll need to repeatedly rinse it.


Btw, I usually use and have best results with BLUE Dawn. I've used green and it doesnt seem to be as effective. I've also used the PRO BLUE Dawn (from Sam's Club). Meh. I think normal BLUE works best.

Larry

I like Larry/LRUCH's approach for the issue.  Great tip Larry!

Thanks Ron!


Btw, are you going to the PC Reunion this September in Vidalia/Natchez?   I'm planning on being there.. Looking forward to meeting everyone and putting some faces to the forum names.


Larry

I'm curious,,, did that unclog your flush jets?

I went the Dawn route, twice. Both with no better results. Took it to a local RV repair shop and they pulled the tank. Said the sprayer & tank was all calcified. Soaked it in a solution then cleaned the sprayer.
But thanks for all the advice. Hope to see you in Louisiana.

Sorry to hear it didn't work,,, twice.  . I never thought about hard water chalking them up.


Yes, I'm looking forward to the rally in Natchez this fall. See you then!


Larry