Unable to completely empty black water tank

[mschatz]

We have been having a very difficult time emptying the black water tank completely.
We have tried putting bags of ice in the tank and traveling to destination. Upon arrival we try to flush and still does not work. Water flows out, but the tank does not empty completely.
Any suggestions????

[PARAPTOR]

How are you determining tank FULL ?? Unreliable gauges ?? Have you searched the forum, many posts on relieving possible solid clogs. Can you tell if your valves are opening all the way

[B-O-B'03]

We have been having a very difficult time emptying the black water tank completely.
We have tried putting bags of ice in the tank and traveling to destination. Upon arrival we try to flush and still does not work. Water flows out, but the tank does not empty completely.
Any suggestions????

What is the indication the tank is not completely empty?

Is the gauge telling you that?
Have you looked down through the toilet, with the valve open and the water off, to see if there is anything in the tank?

The tank level gauges are notoriously inaccurate, it just takes a little bit of TP to create a false indication.

After a trip, I usually fill mine and let it sit for a few days or weeks even and then flush it out with the macerator pump I bought from amazon.

Pretty amazing the stuff that comes out.

-Brian

[fourfourto]

What is the indication the tank is not completely empty?

Is the gauge telling you that?
Have you looked down through the toilet, with the valve open and the water off, to see if there is anything in the tank?

The tank level gauges are notoriously inaccurate, it just takes a little bit of TP to create a false indication.

After a trip, I usually fill mine and let it sit for a few days or weeks even and then flush it out with the macerator pump I bought from amazon.

Pretty amazing the stuff that comes out.

-Brian

I agree take a looky see down the hole you should see the bottom. A flashlight would help.:popcorn:

[bob91yj]

I've had some luck with filling the tank with fresh water and dumping it a couple of times to clear sensors.

[slow]

“He” (no suds) laundry detergent and a few gallons of hot water in the tank when departing for a camping trip has worked well for us to clean up the sensors. Dump and rinse when we arrive at the CG. Do it once a season.

[C.LeeNick]

What I've found is my black water tank will read anywhere from 1/3 to 2/3 after dumping. I take it to mean wet crud clinging to sensors.

After it sits a few days, the "crud" seems to dry out, and the tank will read empty. It was irritating at first, because I've never had an RV with tank sensors before. If they aren't accurate, then what are they for?

Now I just think of them as a toy, not to be taken seriously. I look down the toilet hole with a light, just like I've done in every other RV I've ever had. If I see bottom: Empty.

[hankaye]

mschatz, Howdy;

We have been having a very difficult time emptying the black water tank completely.
We have tried putting bags of ice in the tank and traveling to destination. Upon arrival we try to flush and still does not work. Water flows out, but the tank does not empty completely.
Any suggestions????

First in order to better help you would you please give us the model number,
and year of manufacture. Some 5th wheels have a bend in the drop pipe so
it's almost impossible to see into the tanks. Is it new to you or Brandy new
off the dealer's lot. Have you used one of the "see through" extensions at
the outlet (where you hook the hose up), so you can actually see what is or
isn't coming out of the pipe?
The more you can tell us the better we can help you.

hank

[itat]

We’ve had luck keeping the tanks fairly clean and getting the gauges to read “empty” by using both the
Geo Method (https://sites.google.com/site/cbruni/) and a product called RV Digest-It (https://uniquemm.com/products/rv-digest-it-holding-tank-treatment?variant=73163152).

I also recommend occasionally using a degreaser product like Super Clean (https://www.amazon.com/Superclean-101723-1gal-Super-Degreaser/dp/B01J05YTU2/ref=sr_1_3?ie=UTF8&qid=1541382136&sr=8-3&keywords=super+clean+degreaser) in your grey water tank to get rid of any grease that might have collected from dish washing water.

EDIT: For the soap used for the Geo Method, we use liquid laundry soap in the black tank and liquid dishwashing soap in the grey tank.

[Tufelhunden]

Anyone tried the geo method, dawn and calgon or borax as a softener to clean the tank. Just saw this on YouTube, so it must be great lol, but the idea was interesting as sensor/tank cleaner.

[Bnrc73]

I bought a 10' endoscopic camera on Amazon for around $30. Run it down your toilet and watch on your smartphone to see what's going on in your tank.

[rbrdriver]

Sometimes "looking down the tank" from toilet doesn't work if your toilet isn't directly on top of black tank like a lot of RV's. Then all you will see is a bend in your down pipe.......

[Canonman]

Anyone tried the geo method, dawn and calgon or borax as a softener to clean the tank. Just saw this on YouTube, so it must be great lol, but the idea was interesting as sensor/tank cleaner.

Not sure this is staying on topic for this thread, but to answer your question; we've used the geo method for 6 years with two different campers. No problems whatsoever. IMHO the real key is to get a good complete flush of the tank. Just like the bowl, fill it and flush it and repeat at least once just to be sure.

[realgoodbear]

I have the same problem. I have a clear plastic extension on my discharge pipe with a manually operated valve (due to the issue I'm having). When I flush the black tank, I believe I am doing a thorough job and the water runs clear. Once I believe it is finished draining, I close everything. Once I move the trailer I see light brown water in the clear plastic extension EVERY time. I suppose my problem is really that my factory installed valve is faulty, but if the tank is empty why is there anything still coming out? I have had the trailer in for repair of the black tank valve and they told me it was just "gunked" up and once they thoroughly rinsed it, it was "fixed". I never put tissue of any sort in the toilet, the only thing that goes in there is ummmm.....stuff. It is a 2015 Voltage 3895. Any advice out there?

[JRTJH]

I have the same problem. I have a clear plastic extension on my discharge pipe with a manually operated valve (due to the issue I'm having). When I flush the black tank, I believe I am doing a thorough job and the water runs clear. Once I believe it is finished draining, I close everything. Once I move the trailer I see light brown water in the clear plastic extension EVERY time. I suppose my problem is really that my factory installed valve is faulty, but if the tank is empty why is there anything still coming out? I have had the trailer in for repair of the black tank valve and they told me it was just "gunked" up and once they thoroughly rinsed it, it was "fixed". I never put tissue of any sort in the toilet, the only thing that goes in there is ummmm.....stuff. It is a 2015 Voltage 3895. Any advice out there?

Think about the breakfast dishes: If you have grits, eggs, bacon and toast with grape jelly, let the plates sit on the table for an hour (drying the egg yolks on the plate surface) then move them to the sink, run them under the faucet for a few minutes, then hold them up for "inspection".... Will they be "clean" or will you still see "bits and pieces of bacon encrusted with yellow egg yolk" still dried on the plate surfaces ???

You'll "never" (yes, this is one time you can say "never say never") get the entire contents of the black tank "clean" by flushing with clear water under "kinda medium spray pressure"....

Essentially, you'll always be able to add a couple gallons of water, slosh it around by towing and expect it to come out "tainted by brown stains"......

Since there's no means to use "mechanical scrubbing action" to move "stuff" off the inside walls of the black tank, it'll never be "breakfast plate clean" when the little bit of cold water rinse is finished......

[Tufelhunden]

Not sure this is staying on topic for this thread, but to answer your question; we've used the geo method for 6 years with two different campers. No problems whatsoever. IMHO the real key is to get a good complete flush of the tank. Just like the bowl, fill it and flush it and repeat at least once just to be sure.

I mentioned it for two reasons, one to help the person saying their tank is not getting cleaned and two to see if it actually works, from other RVers, before they try it. ;)

[UsTwo]

yea I use the Geo method.. Well started out using it.. but now have my own Geo method..I use Gain fabric softener, dawn, and what ever else I feel like throwing down there,,.. Like John said above, Quote "You'll "never" (yes, this is one time you can say "never say never") get the entire contents of the black tank "clean" by flushing with clear water under "kinda medium spray pressure".... End Quote.. I understand this, and even using the black tank sprayer and a top side swivel head sprayer a couple time a year it still never comes really clean.. But dang it sure does smell good. lol

[KSH]

I bought a 10' endoscopic camera on Amazon for around $30. Run it down your toilet and watch on your smartphone to see what's going on in your tank.Which one? Water proof?

[itat]

yea I use the Geo method.. Well started out using it.. but now have my own Geo method..I use Gain fabric softener, dawn, and what ever else I feel like throwing down there,,.. Like John said above, Quote "You'll "never" (yes, this is one time you can say "never say never") get the entire contents of the black tank "clean" by flushing with clear water under "kinda medium spray pressure".... End Quote.. I understand this, and even using the black tank sprayer and a top side swivel head sprayer a couple time a year it still never comes really clean.. But dang it sure does smell good. lol

Calgon is a water softener. Fabric softener is not the same as water softener. Water softener makes the inside walls of the tank slippery inhibiting solids from sticking to anything inside, including the sensors, and making the flush more effective. As I said in post #9, I also use a bacteria product called RV Digest-It to help break down the solids in the tank. Another popular product that’s similar is called “Happy Camper”.

I agree that it’ll never be totally clean though.