Trouble draining black tank

[richeyb]

Started draining black tank after 3 days camping. It appeared to be draining but when I pumped water through the Black tank flush the gauge stayed at 3/4 and none of the new water I added will come out. Appears to be plugged up somewhere. I drove home 2 Hrs thinking the bumps would help but still no drainage!
Any thoughts or tricks to try? Montana HC 380.

[jimcol]

Forget the gauge. They hardly ever work in the black tank. How did you determine that what you added wasn't coming out?

[Neverhome]

Did you have the tank closed during those three days or did you leave it open? If you left it open you most likely have the dreaded paper pyramid. That being a dried out pile of pooh and paper that is going to be time consuming to remove. If it was closed and you are sure it is still full and you are not relying on the gauges that never work, you may want to ask if anyone threw anything other than toilet paper in there. Feminine napkins or baby wipes are prime reasons for plugging black tanks. There are several products available that can help clear out the clogs. I suggest you contact you local RV center for advice on what works best.


Good luck.

[richeyb]

Thanks for the replies. I determined there was no flow out By watching the clean connector going into the ground. I normally do the black tank flush and watch for it to flow clear. Only problem with the Flush still on there was no flow.

Any idea how far below the tube that extends from the toilet into the tank is the bottom of the tank or the top of the tank?

[Texan]

Get you a water hose' preferably garden hose with a twist nozzle' and turn wide open and stick it as far up in the drain as possible. If your stoppage is where the water comes out of the tank into the drain then hopefully the high pressure from the nozzle will wash out whatever is stopping it up.

[mazboy]

so many questions. how many days did you have it closed before you dumped?


and, we've never used the gauge....usually wrong, even if it works.


we usually dump when nearly full, there are 2 of us and that is usally about 2 weeks or when it starts to burp. and it really does burp.

[RMcNeal]

richeyb, try using a Flush King to back flush the tank. I have used one since we started with our TT years ago. Works very well to flush black and gray tanks. It's on our "must have" list of accessories. https://www.amazon.com/Valterra-Degr...s%2C291&sr=8-3

[mlh]

The golden rule for black tank, lot of water little paper.
Lynwood

[Gary F.]

this will clean paper off sensors and help clear tank works great better than tank flush on unit.

RV Flexible Swivel Stik
$19.97 $28.99

[KRSEGUINE]

I sometimes put a little active yeast down the toilet. When I drain I don't drain it all. That way the yeast environment will continue. I've done this for a couple of years. No dreaded pile up.

[Graham]

I agree with Robert and Dianne...the backflush adapter is well worth it. We park our RV all summer at Shuswap lake in Canada. Things get built up and the back flush puts pressure on the blockage. Works great.

[Docweems]

I have also used the flexible swivel stick with good success. When I have had a really plugged up black tank, I have also used a non drinking water hose and a stream nozzle that is non adjustable on the end of the hose. Threaded that down into the black tank and tried to get it into the general area of the discharge hole on the black tank and then turned on the water and continued to "work it " around. I have usually been successful. It is messy but at least it it worked and then I really flushed the tank out.

[richeyb]

After adding a cup of Redix and a couple of RV pods and letting it sit for a couple days the gauges started to work and I was able to flush out the tank. All clean! I think lesson learned is to use more water in the normal use of the black tank. Thanks for your comments.

[DutchmenSport]

Don't know how your drain pipes are configured. I've got 3 valves. One is for the kitchen sink in front of the tires. The other two valves are tied together in a single outlet behind the tires.

All my campers in the past have always had the black and grey tank valves run together to one outlet. I learned early a simply, quick, and water saving method to keeping the black tank flushed out, very, very well.

I purchased a Flush King valve that bayonet mounts to the drain outlet. The Flush King type valve has a clear section so you can always see what's coming out. Attach the Flush King type valve and do the following.

Close the grey tank valve and drain the black tank completely until it stops or almost stops running. The water is gone. BUT... there is still stuff on the bottom of the black tank ... after you've done this a few times you'll never NOT do it again.

Once the black tank finishes, close the Flush King valve and now open the grey water valve. The grey tank is full of water, the black tank is not. Water runs down hill. As soon as you open the grey valve, the grey water will back-flush into the black tank. This takes only about 5 to 10 seconds and then close off the grey tank again.

The grey water back flushing into the black tank will help break away any residue left on the bottom of the black tank with the backward “swish”.

Now, open the Flush King valve again and let the black tank drain again. Once it finishes draining, repeat the back flush. If your grey tank is full, you can comfortably back flush 3 times. Each time, more and more, and more “stuff” will come gushing out of the black tank. And you’ll never go back to a simply flush once and go again when you see how MUCH is still in the tank with only the initial draining.

After the 3rd back flush, close off the black tank valve and finish draining the grey tank to clean out the sewer hose.

After you’ve done this a couple times, you’ll find it goes pretty fast. Once you see how much comes out the second and third time, you’ll be taking longer showers so you’ll have more water in your grey tank so you can back flush a 4th or even a 5th time. And YES, I have found by trial and error that back flushing pulls a lot more out of the tank than my black tank flusher. With that clear section in the Flush King, you can easily see what’s coming out.

If you have the luxury of time, follow up with your black tank flusher. As a final, add water to the tank, add a half cup of Dawn Dishwashing liquid down the toilet and head to your next destination. Your sensors will always work.

[TDury]

I had a similar issue and climbed on top of the RV and removed the cap on the vent pipe over the bathroom. I then took a hose and shot water down the vent pipe. Problem solved. Just be sure to get the cap back on tight!

[Daryles]

I have a Valterra twist on gate valve. No more surprises when I take the cap off and I do what DutchmenSport does. Very effective.
When putting away the rig for a while I will raise the front end of the rig. This helps drain the black tank (more downhill slope).

[margerush]

I use Calgon water softner (Wall Mart) and sometimes a cup of laundry soap mixed with 5 gal of water. Pour these down toilet. Drive the monty around for a bit to swish everything around. Drain the black tank. Might have to add Calgon a second time for bad pyramid. Good luck