Black holding tank will not drain

[Danielflading]

Hello all,

Dan here from Houston area, I am having a problem getting the black holding tank to drain. The monitor panel shows 2/3 full and when the potty is flushed you can see the tank has contents in it. went to a dump station and tried to dump black tank and only a few gallons came out. the Grey tank did drain completly. Only the black tank is having a problem.
I did run a water hose up into the drain and I am sure into the tank as well, I pushed about 6 feet of hose into the drain still nothing. The black holding tank is only about 1-2 feet from the drain so i know the garden hose went into the tank. It has not been dumped for some time we bought it used and did not know the tank had a problem.
We bought the camper AS-IS so I am on my own to get this tank to drain. I am putting the toilet chemical in tonight to see if it will brerak anything down that may be causing a blockage.

if you have any ideas or suggestions to get the tank drained, please let us know.

Thank you for any help,

Dan and Kelly

[revrnd]

It's possible that there is a lot of "solid mat'l" accumulated on the bottom of the holding tank. I have read on the 'net where folks that dry camp & try to minimize their water consumption. They end up w/ not enough water to loosen the "mat'l" & they wind up w/ a mound in the tank.

Do a search for Calgon and/or Geo Method on this forum. Some tips for dealing w/ sewage issues. You may have to do a couple of fill/drive/dump trips to try to empty the tank.

[Danielflading]

Thank you for the information I am thinking the same thing, I just put a few gallons of water and chemical into the potty will do a drive and dump again tomorrow.

Dan nad Kelly

[NWJeeper]

X2 what Revrnd posted.

However I would never advise putting a hose up the drain pipe, unless you plan on throwing that hose away when you are done. The more preferred method is to run water down the toilet with a hose (don't cram it down there for the same reason) and or use a cleaning wand available at many RV supply stores for just such a purpose.

[NWJeeper]

I just remembered another idea that others have used. Fill the tank half full and pour a bunch of ice down, go drive around, the hard ice sloshing around can help knock things loose.

[Iggy]

Someone may have dropped something solid down into the tank and at times covers the botton 4" hole which would stop the rest from draining. Piece of plastic or maybe a toy from the last owners kid.

Good luck

[revrnd]

Or that pop/soda can that someone posted about recently.

[Danielflading]

Yes I threw the hose away, it was old and useless anyway. i thought something may be blocking the outlet and the hose would move it aside. A friend was also suggesting the ice method, may try that tomorrow.

Thank you for the help!

[jd-ford-hd]

This is an excellent example of why you don't camp with the black valve open..! I have seen countless people in an RV park set up with their black valve open. Valve should stay closed till the black tank is 1/2 full or better and then dump as soon as you get off the road while solids are still suspended in the liquid, then, close black valve, then, drain the gray to rinse the hose with your soapy bathwater, then close gray valve and the cycle starts over.

[Emptypockets]

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