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Topic: Need Suggestions on Clearing Black/Grey Tanks Blockage (Read 661 times) previous topic - next topic
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Need Suggestions on Clearing Black/Grey Tanks Blockage
Got a call from my sister in law. She is living in a SOB class C. It has been parked for about 6 months at a rv park on full hookups. She parked it and hooked up to sewer and left both gray and black tank valves open. Well she calls because the tank won't drain lol. I imagine the black tank is packed full like an outhouse. Any ideas on what I can tell her on how to unplug this mess? She says even the gray water won't drain. I'm guessing even the pipe are plugged full.
Lynn and Lori
Re: Need suggestions!
Reply #1 –
My goodness.  I mean HOLY MOLY.  What an awful problem.  I'm guessing the solution is going to be massively dirty and unpleasantly expensive.  I sure hope someone has some solutions. 
  😱😱😱

EDIT NOTE:

I had recommended a black tank cleaning service and within 30 minutes of visiting that particular site, I received a junk email with my phone number from that site recommending their product .    I've edit this post by deleting reference to that site.   I also ran several AV scans and the scans report I'm clean.  Nasty stuff for sure.
Re: Need suggestions!
Reply #2 –
Sounds like a probable blockage in the sewer or sewer hose.   Perhaps close both black and gray dump valves and disconnect the sewer hose over a bucket (catch spills) to see if the blockage lies in that part of the system...Remember to wear gloves and a clothesline peg on the noses!

Matt
Re: Need suggestions!
Reply #3 –
Depending on the geometry of the plumbing outlet, one of those clear fittings with an integrated hose fitting may help.  Use it to either backflush with the hope of clearing the blockage, or as an inlet for a snake.  I'd stick with hand-powered on the snake, to avoid unplanned penetration of the protective perimeter (drilling thru the tank or hose). That's if the blockage is in the outlet path.  It could very well be a more widespread issue, in which case it's time for a trade-in. 

Chip
2000 Front Lounge
Re: Need suggestions!
Reply #4 –
Fill the gray and black tank through the dump valve.  This should loosen things up a bit.   Buy  another sewer hose.  Try the gray first so the black doesn't plug the new hose.  Then try the black.  If it won't flush hire one of those trucks set up to suck up sewage into the tank on the truck.  Run the hose down the toilet and empty the tank.   Fill and repeat - a few times.

Or, try to find and rv shop that will do it.  And be prepared to pay $$$$.      Frank

plan B - 2023 Travato
Re: Need suggestions!
Reply #5 –
Here is a much easier solution than dealing with the one at hand:

Remove the cat and your sister's essential belongings, turn on the gas, leave a little pilot light on somewhere and go to the movies.
Tell the insurance adjuster that she has no idea what happened, but maybe the black tank was plugged up and swamp gas filled the coach. Take the money and move to a better climate and get a nice little condo with a nice view.

HD
2014 27 MB
Towd: Either the Jeep Wrangler or trailer containing the BMW R1200GS and 2 E-bicycles
Happy wife=Happy life
Re: Need suggestions!
Reply #6 –
Here's how I would approach it:

1) At an RV parts store, buy a Valterra Flush King, a new sewer hose and a hose backflow preventer
2) At a hardware store, buy a five-gallon bucket, a garden hose, two or three pairs of sturdy, long rubber gloves, a box of nitrile gloves, one or two packages of bleach disinfectant wipes and a pair of safety glasses, goggles, or shield
3) Clear the area between the valves and the sewer inlet of all items that could complicate cleanup
4) Have a trash can with two trash bags installed handy
5) Change into your worst clothes, then don the nitrile gloves, rubber gloves, and safety glasses
6) Close the black and grey water valves
7) Move the hose back and forth, side to side along its length to break up any blockages
8) With the five-gallon bucket nearby, gently remove the end of the hose from the sewer inlet. If you can, leave it ajar enough to have the effluent go down the inlet, but to have little or no flow onto the ground. If you have to, put the sewer hose end in the bucket. If the flow does not stop before the bucket is half-full, put the sewer hose back on the sewer inlet. (At this point one would assume the tanks are draining- perhaps slowly- and that the valves are leaking). Hopefully, this process drains what it can from the hose.
9) Remove the sewer hose from the valves. Throw it in the trash can.
10) Install the Flush King, backflow preventer, garden hose and new sewer hose
11) Backflush the grey water tank
12) Backflush the black water tank
13) Remove Flush King, backflow preventer and garden hose
14) Attach new sewer hose to valves
15) Change to new nitrile gloves and rubber gloves
16) Clean up with disinfectant wipes (soap and water with a disposable sponge afterwards would also be wise)
17) Clean and disinfect area around sewer inlet
18) Throw away the used gloves and anything else too soiled to use again
19) Don't leave the black water valve open again, and think carefully about whether it's prudent to leave the grey water valve open. I don't leave leave the grey water valve open, although some neighbors do.

Mark
Former owner, 31-foot gas Class A
Former owner, 1997-8 mid-bath
Re: Need suggestions!
Reply #7 –
Thanks for the suggestions!  A little more information I had her pull the hose and it is clear. Black and gray are both over full. Black is backed up to the ball in the toilet and gray starting to come out of drains. Boy I am glad I am 100 miles away from this mess.
Lynn and Lori
Re: Need suggestions!
Reply #8 –
Sounds like she is ready ready for step 10).   Hopefully the slide gates will open.
If not it has been discussed some place on the forum.
Rodney
1988 Mid Bath
 
Re: Need suggestions!
Reply #9 –
Maybe the suggested clog clearing measures can work, but I really doubt that there is a viable solution to the 'impaction' other than hiring a pump-out company to (try to) suck out the tank(s); if the black tank contents are up to the toilet ball, this will be a 'big job', and one which a company may well decline to take on. If she finds a tank truck willing/able to do this, hold the toilet valve open while the pumping takes place; if the pump can break up and suck out the mass at all, one surely doesn't need the additional potential misery of the tank imploding.

Give a whole new meaning to the term 'big block'!  ;)
2003 TK has a new home
Re: Need suggestions!
Reply #10 –
Quote from: JCT  - 
Maybe the suggested clog clearing measures can work, but I really doubt that there is a viable solution to the 'impaction' other than hiring a pump-out company to (try to) suck out the tank(s); if the black tank contents are up to the toilet ball, this will be a 'big job', and one which a company may well decline to take on. If she finds a tank truck willing/able to do this, hold the toilet valve open while the pumping takes place; if the pump can break up and suck out the mass at all, one surely doesn't need the additional potential misery of the tank imploding.

Give a whole new meaning to the term 'big block'!  ;)


Yep I am guessing that the black tank is totally impacted after 6 months with very little liquid in it. I don't know if it would even be possible to suck out that big solid block. But I agree it would be worth a shot.
Lynn and Lori
Re: Need suggestions!
Reply #11 –
  After reading the other ideas and comments, I like the honey truck "suck it out"  idea best.  If you can get it started and then add water to liquify it should work.  The gray tank...  work it out from the drain valve.  No other choice with the gray.

what a job...     Frank
plan B - 2023 Travato
Re: Need suggestions!
Reply #12 –
"Boy I am glad I am 100 miles away from this mess."

Let's hope that's far enough.

2000 Front Lounge
Re: Need suggestions!
Reply #13 –
I am guessing that both black and grey use a common connection point.  That being the case, and since the drain hose is clear, I would borrow or buy something like the Valterra Hydroflush connection.
Valterra Hydroflush Reverse Flush Adapter for RV Holding Tanks and Sewer...

With that, and with the drain hose connected to a sewer dump, I would close the black tank valve, open the grey tank valve, connect a garden hose, turn on the hose, and open the spray valve.  It cannot back up into the tank because there is nothing to block the outflow.  Let it run for a while.  The jet of water is likely to chew away at the blockage between the bayonet connection and the grey tank valve.  Once it reaches beyond the blockage from the black tank, the grey tank will dump.

After the grey tank dumps, close the grey tank valve and open the black tank valve.  Then just let the jet of water run for a while.  It could take a LONG time to chew out enough of the blockage to make a difference.  The idea of pushing a hose into the mass from the toilet to break it up might work, but if water is running through the hose, it is more likely to trigger an overflow at the toilet.  You need to break the mass up from underneath.

While the surface of the blockage may tend to be harder, the core is likely to be softer.  Once it becomes exposed to water movement I suspect it will break up fairly quickly.  In any event, you will be able to see if the tank contents are being removed by the appearance of the outflow through the clear plastic. 

If you have gone a day and the outflow has been running clear with no indication that any of the mass has been broken up, you need a pumping service.  Turn off the water and call a pro. 

If the outflow ran cruddy for quite a while, and is now running clear, you will have cleared out some of the blockage.  At that point, try hot, soapy water dumped into the toilet bowl, and try to flush it into the tank.  If it goes in, close the black tank valve, turn off the water, and add hot soapy water until it is up to the toilet base, then let that sit overnight.  Turn on the water jet and dump.

Repeat the above, soaking overnight with the valve closed, then dumping with the black tank valve open and the water jet running, until the outflow you get seems to run clear or nearly clear.  At that point I would get some Rid-X or similar, dissolve a portion of the package in warm water (remember, that package is designed for a septic tank that holds hundreds of gallons, not for an RV tank holding perhaps 25 gallons), fill the black tank with warm water and add the Rid-X solution.  Let it sit for as many days as you can, ideally for a week or more.

That should soften all residue remaining in the tank.  You need to flush that out.  Open the black tank valve and dump the contents that have been soaking.  Turn on the water jet.  Now, try to flush the tank from the toilet using something like this:
Swivel Stik RV Black-Water Tank Rinser w/ Flexible Extension Camco RV Sewer...
That is what I use, and it seems to work fairly well.

Good luck with this.  You may need multiple soaks before the tank is completely clean.  If you can get enough of a breakup of the mass that you can add water at the toilet, this is something you can clear on your own, but if you can't get it clear enough that you can add warm soapy water to the toilet and have it flow into the tank, you need a pro.

For what it is worth, I know someone who had a blockage in their line either at the black tank valve or from there to the junction with the grey tank.  His solution was to get a full rain suit, a Walmart cheap-o, then gloves and a face shield.  He parked at a dump station with a large concrete apron, opened the bayonet cap, opened the black tank valve, hooked up a hose, and fed the hose, water running through a spray nozzle, up the line until he felt resistance.  He then ran the hose back and forth, using it like a plumber's snake, working through the clog.  He finally broke through into the black tank and waste began to flow onto the apron.  He left the hose in place, water running, while his DW watched from inside to make sure nothing was backing up.  The flow from the black tank increased, running slowly at first, then faster as the clog cleared.  Eventually it was running fairly clean, at which point he removed the hose, rinsed down the concrete apron, threw away the hose and nozzle, closed the black tank valve, and did the fill-soak-flush routine until he felt sure that the system was clear.

He was NOT a happy camper, but for a few $$ he managed the clear the blockage.

Ken F in UT
'08 MB
Re: Need suggestions!
Reply #14 –
Thanks Ken I am going to copy your post and send it to her.
Lynn and Lori
Re: Need suggestions!
Reply #15 –
Quote from: Duro  - 
Thanks Ken I am going to copy your post and send it to her.

If Sister-in-Law is successful then that's going to be great news.  If she has to call a professional service, then it will be interesting if that's successful.  And finally, regardless of which strategy works or doesn't work, Sister-in-Law has learned a valuable and unfortunately a painful lesson.   For what's it worth, Margee and I have a clear memories of many painful lessons.
Re: Need suggestions!
Reply #16 –
I was also wondering if to add insult to injury, she puts her TP into the black tank, and is careful what she puts into the grey tank... add that to the obvious could make it a lot worse blockage..wishing her luck!!

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Gini Free and Junah, canine xtrodinaire "CHERRYOTTE" our litte red home on wheels "Growing old is mandatory. Growing wise is optional."
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Gini Free and Junah, canine xtrodinaire
"CHERRYOTTE" our little red home on wheels
"Growing old is mandatory. Growing wise is optional."
Re: Need suggestions!
Reply #17 –
Quote from: Gini Free  - 
I was also wondering if to add insult to injury, she puts her TP into the black tank, and is careful what she puts into the grey tank... add that to the obvious could make it a lot worse blockage..wishing her luck!!

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Gini Free and Junah, canine xtrodinaire "CHERRYOTTE" our litte red home on wheels "Growing old is mandatory. Growing wise is optional."

Oh no she used no care in what she put into the system. She said "I thought anything was OK because I was hooked to sewer".
When she bought the RV I tried to explain some things to her. But she is kind of a know it all until something goes wrong LOL.
Lynn and Lori
Re: Need suggestions!
Reply #18 –
So much said about this problem. I believe Mark said it best "Don't leave the Black Tank Valve Open" between dumping the tanks.

I'd go as far as saying "Don't Leave Either Valves Open" between dumps.

The Black tank needs water/fluids and enzymes in it during use to prevent solid matter build up and to help break down paper, liquids and solids. Typically the Black Tank needs to be 3/4 full before dumping.

Another reason to keep the valves closed between dumps is to eliminate to sewer gasses and flying insects from infiltrating the tanks, toilet and the coach itself.

Simple precautions that can help eliminate future issues.

Good luck with the situation.

Kent
2015 27' RB "MissB.Haven"
Re: Need suggestions!
Reply #19 –
Quote from: Duro  - 
Got a call from my sister in law. She is living in a SOB class C. It has been parked for about 6 months at a rv park on full hookups. She parked it and hooked up to sewer and left both gray and black tank valves open. Well she calls because the tank won't drain.

By chance ... any updates?  This is one of those situations in which I anxious to hear the outcome.
Re: Need suggestions!
Reply #20 –
Quote from: Traxless  - 
By chance ... any updates?  This is one of those situations in which I anxious to hear the outcome.


I sent all the info to her that was posted here. She was going to try to clear it and if that didn't work call a pump out company. I haven't heard from her so I hope she got it cleared out.
Lynn and Lori
Re: Need suggestions!
Reply #21 –
Any update on this?

Ken  F in NM
'08 MB
Re: Need Suggestions on Clearing Black/Grey Tanks Blockage
Reply #22 –
Once again...One of the best things about LDO is the "Well Of Knowledge" that it's members openly share.

After that, it is up the the recipient to do with as they please.

This thread, in particular, is of vital importance and can be of great help to many new to RV living. In fact, I thought back to this thread just yesterday when I cautioned my older brother to "keep your tank valves closed" when hooked to a sewer connection. And, "Don't dump your black tank until it's at least 3/4 full". And, and, and...

He just purchased his first Class C. Not a LD, but oh well some of us just can't wait. I'm hoping that he is open to suggestions just as we hope Duro's sister is.

We can always hope.

Kent
2015 27' RB "MissB.Haven"
Re: Need Suggestions on Clearing Black/Grey Tanks Blockage
Reply #23 –
I passed my beloved Lance camper to my daughter and son in law yesterday and showed them how to use all of the appliances and features and how to dump the tanks.  I showed my son in law this thread and explained how he should manage his waste tanks and dump in order to avoid Duro's sister in law's dilemma.  I also shared that if he gets his black tank stopped up, he will fix it himself.  We will see if he heard me and understood on our trip next week!

HD
2014 27 MB
Towd: Either the Jeep Wrangler or trailer containing the BMW R1200GS and 2 E-bicycles
Happy wife=Happy life