Black tank issues!

[Ryan44CW]

Please help! I can fill my black tank up through the flush connection and pull the lever and it drains. The problem is, the top half is full with waste and not draining. I've tried using a snake, it worked once but it's happening again and not working now.

 

[JudyJB]

Are you saying that the bottom half of the tank is empty, but the top is full of a solid chunk of waste than will not drain? That sounds very unusual. I have had dried piles of toilet paper in my toilet that would not flush out easily, but they were in the bottom of the tank, not the top.

And is your flush connection something you attach a hose to on the outside of your rig? Or is it something you put a hose on inside of your bathroom?

When you turn the water off and use a flashlight to look down through your open toilet drain, can you see this waste or is there a bend in the pipe? If you can see the waste, you might be able to stick a metal rod down there and poke at it to break it up. Then you might add some water and let it soak for a while to loosen stuff up enough to make some of it drain.

Solid waste is usually a result of family members not flushing enough water when they use the toilet It could also be caused by living in a dry climate and letting the stuff sit for weeks or months, which would cause it to dry up, so you should always drain your black tank as much as possible before you store it and then leave several gallons of water in it.

I am lucky in that I can see down the drain into my toilet, so I used the metal rod to stir things and then added water and drove around, making hard stops and swerving to slosh things around. (Best to do this on an empty rural road so people do not think you are drunk or slightly nuts.)

There are companies which will use high pressure to break up chunks of stuff in your toilet. Check with your local RV service place for a referral.

 

[Ryan44CW]

Are you saying that the bottom half of the tank is empty, but the top is full of a solid chunk of waste than will not drain? That sounds very unusual. I have had dried piles of toilet paper in my toilet that would not flush out easily, but they were in the bottom of the tank, not the top.

And is your flush connection something you attach a hose to on the outside of your rig? Or is it something you put a hose on inside of your bathroom?

When you turn the water off and use a flashlight to look down through your open toilet drain, can you see this waste or is there a bend in the pipe? If you can see the waste, you might be able to stick a metal rod down there and poke at it to break it up. Then you might add some water and let it soak for a while to loosen stuff up enough to make some of it drain.

Solid waste is usually a result of family members not flushing enough water when they use the toilet It could also be caused by living in a dry climate and letting the stuff sit for weeks or months, which would cause it to dry up, so you should always drain your black tank as much as possible before you store it and then leave several gallons of water in it.

I am lucky in that I can see down the drain into my toilet, so I used the metal rod to stir things and then added water and drove around, making hard stops and swerving to slosh things around. (Best to do this on an empty rural road so people do not think you are drunk or slightly nuts.)

There are companies which will use high pressure to break up chunks of stuff in your toilet. Check with your local RV service place for a referral.

Yes The flush connection is something I hook the water hose up to on the outside to spray the inside of the tank.
I have a bend in the tank so I can't see down in it.
I've used a snake and it only goes so far into the pipe, I'm curious if I'm hitting the bottom of the tank, but that wouldn't make sense because why would I have standing waste in the top half of my pipe leading into my toilet.

Could there be a solid hardened blockage in the pipe preventing it from getting into the tank?

If I let it sit for a while the level will go down but it feels very quickly again

 

[Rene T]

What makes you say the top half is full of waste
Do you have a clear elbow outside where you connect your sewer hose? If not, get one. This really helps when dumping and flushing. You keep doing it until clear water runs out.
If you are saying it is full because your gages say full all the time, stop relying on those gages. If they are the type that penetrate the wall of the tank, they are notorious for reading wrong. They build up with waste on the inside of the tank giving false readings.

 

[Rene T]

I see you are new to the forum so welcome. Are you new to rv’ing?

 

[John From Detroit]

How do you know the "Top half" is full.. Toilet not draining?
Seen that once. was a toilet clog or clog in the drop pipe the tank was empty I'm talking EMPTY.

 

[SMR]

Since you can't see into the tank what are you using to determine its half full.
Can you pour water into the toilet and see if it is draining out.
I would also check the vent to make sure there are no obstructions

 

[Gary RV_Wizard]

It's all but impossible that the "top half" remains full while the bottom drains, unless you have two physical tanks making up the rated capacity. I've seen that for gray waste tanks, but not black. The amount of semi-solids in the black waste makes that impractical.

Please tell us more about how you concluded the "top half" remains full? Gauge readings? Measured volume when dumping? Try this: Dump the tank contents until draining stops. Leave the drain hose connected & valve open and flush the toilet for a continuous 60-120 seconds. Does water exit the black tank?

 

[JudyJB]

As Rene suggested, I suspect that you are using the lights on your monitor panel to determine that your tank is blocked on the top. Nearly all the monitors use sensors in or on the outside of the tanks, and a chunk of toilet paper or something can easily stick to the side of the tank where that sensor is, and that causes the monitor to think the tank is full.

In fact, right now, after I have recently dumped my black tank, I am showing one light showing that the tank is almost empty and two at the top of the panel showing it is full. There are two other unlit lights in between which means that the tank is really almost empty, but that there is some gunk stuck to the top of the tank where the top two sensors are located.

Sometimes, using the spray flush thing, or even filling the tank up with clean water, leaving it alone for a while and then dumping the whole tank out will clear this up. (Driving around a bit with a full tank will also help.)

After some experience, you will learn to trust or not trust the tank sensors.

 

[L-M-L]

We have had a problem with our system backing up. The drain from our toilet to the black tank has two 45-degree bends. I thought we had something obstructing it. I ended cutting the pipe above the bottom 45. What i found on ours is the tank has a shelf that must go over the frame. The pipe drains into the tank over the shelf area and there is not much clearance where the pipe goes into the tank and the bottom of the tank. If we do not use enough water it builds up and clogs. Have not had luck using a snake. Flushing the tank or pulling the camper down the road with about half a tank of water will wash out the debris.

 

[Kirk]

Could there be a solid hardened blockage in the pipe preventing it from getting into the tank?

I agree with Gary's response. If you are seeing something when you look down the toilet but you are still able to flush the toilet when used, there must be some water remaining in the pipe as it would be pretty obvious if toilet paper and human waste was staying in the pipe and you would soon not be able to flush the toilet. Is this a used RV that you just purchased? Have you towed it anywhere yet? A good way to clean the waste tanks is to fill them about half full of clean water, with a strong dose of laundry detergent and then drive 20 miles or so and dump as soon as you arrive. It has been my experience that very little residue remains in the tanks when that is done.

 

[Ryan44CW]

How do you know the "Top half" is full.. Toilet not draining?
Seen that once. was a toilet clog or clog in the drop pipe the tank was empty I'm talking EMPTY.

Bingo! And guess what It was a wad of toilet paper! I had to take apart the pipe underneath and it was stuck right at the valve opening. Before that I had got it unclogged from the top half and then it got clogged up trying to leave the tank.
I accidentally bought the wrong toilet paper and thought I would be fine, I was very very wrong. It was not a pleasant job but it is fixed and now

 

[Ryan44CW]

How do you know the "Top half" is full.. Toilet not draining?
Seen that once. was a toilet clog or clog in the drop pipe the tank was empty I'm talking EMPTY.

Yup!

 

[Ryan44CW]

It's all but impossible that the "top half" remains full while the bottom drains, unless you have two physical tanks making up the rated capacity. I've seen that for gray waste tanks, but not black. The amount of semi-solids in the black waste makes that impractical.

Please tell us more about how you concluded the "top half" remains full? Gauge readings? Measured volume when dumping? Try this: Dump the tank contents until draining stops. Leave the drain hose connected & valve open and flush the toilet for a continuous 60-120 seconds. Does water exit the black tank?

It's fixed now. But the top half was full because there was standing water in my toilet even after I drained the tank. Turned out to be a huge wad of toilet paper stuck in the top pipe not allowing stuff to drain into the tank.

 

[Ryan44CW]

As Rene suggested, I suspect that you are using the lights on your monitor panel to determine that your tank is blocked on the top. Nearly all the monitors use sensors in or on the outside of the tanks, and a chunk of toilet paper or something can easily stick to the side of the tank where that sensor is, and that causes the monitor to think the tank is full.

In fact, right now, after I have recently dumped my black tank, I am showing one light showing that the tank is almost empty and two at the top of the panel showing it is full. There are two other unlit lights in between which means that the tank is really almost empty, but that there is some gunk stuck to the top of the tank where the top two sensors are located.

Sometimes, using the spray flush thing, or even filling the tank up with clean water, leaving it alone for a while and then dumping the whole tank out will clear this up. (Driving around a bit with a full tank will also help.)

After some experience, you will learn to trust or not trust the tank sensors.

I'm not looking at the sensors. I'm not a beginner

 

[Kirk]

But the top half was full because there was standing water in my toilet even after I drained the tank. Turned out to be a huge wad of toilet paper stuck in the top pipe not allowing stuff to drain into the tank.

Which indicates that the plug was "in the top pipe" so the tank was draining and the pipe was what didn't drain.

 

[Gary RV_Wizard]

I accidentally bought the wrong toilet paper and thought I would be fine, I was very very wrong.

The toilet paper is always a popular topic here. Would be interested in which one you feel is "wrong".

Some RVs simply have poorly designed and/or assembled toilet waste lines. RV design is more about ease of manufacturing than effective use. Angled pipes, ridges at joints, weak tank fittings, etc.

 

[Ryan44CW]

The toilet paper is always a popular topic here. Would be interested in which one you feel is "wrong".

Some RVs simply have poorly designed and/or assembled toilet waste lines. RV design is more about ease of manufacturing than effective use. Angled pipes, ridges at joints, weak tank fittings, etc.

Just the plush toilet paper made by Scott. I will say it's the first time I used it in the camper and this the first time it clogged up. That's why I think it's wrong kind.

 

[woof-n]

Ryan44CW
Thank you for sharing what you did to resolve your problem. People often come here looking for help but sometimes once they resolve the problem, poof there are gone. There is a number of people here that continue learn new RV repair solutions from situations like yours to share with others.

When purchasing a new brand of TP, I put one square of TP in a glass of water and wait 5 minutes. I then take a spoon and stir the TP in the water. If the TP dissolves into little bitty pieces, I will use it in the camper. If it wraps around the spoon, I use it in the home. NOTE I have found some RV TP that it wraps around the spoon. I don't care what the label says, if it does not mostly dissolve in 5 minutes, don't use it in the RV. Dennis

 

[Gary RV_Wizard]

As a general statement, TP that is quilted, embossed, colored or patterned is made from stronger papers that are harder to dissolve. And multi-layer papers simply have more paper per square of tissue, so more to dissolve. They can all be labeled as "septic-safe" but they are still harder to process thru an RV holding system than plain old single ply white. An RV system that has multiple 45 angles or poorly fitted joints is more susceptible to paper clogs, so a paper that works fine in one rig may be problematic in another. And last, each person's TP usage plays a significant role in clog potential.