Black tank showing full after discharging (found fix)

[Kegan]

My black tank indicator was showing nearly full after emptying. My dilemma was it really empty (as I thought it was) or was something jammed up in the hose that was preventing discharge? Not wanting to do any exploratory surgery on the black tank, I was perplexed. And then I was given this tip ..... dump a few pounds of ice down the commode and go for a drive. I was told that sometimes a piece of TP may get hung on the sensor creating a condition where the tank seems full when it is not. The above tip worked for me. The ice jostled the sensor gremlin..... hope it helps.

[rowiebowie]

Good tip. My unit has a sani-flush attachment that I use periodically as a precaution. Hooked up a presurized water hose, there is a multi-directional sprayer head in the tank that rinses it out well.

[rvsprinterguy]

Ice down the toilet is a good tip. I'll give it a try because I almost never get a true reading right after dumping. Eventually it seems to settle down.

I like the idea of being able to spray-clean the inside of the tank. I've seen others at dump stations attaching a hose to a fitting higher than their black tank could be, and running water through it. They must have the Sani-flush installed. I'l try to spec this feature on my next unit.

[theHueg]

If you have an in-tank spray head, be sure to use a pressure limiting connector. Before I learned this, I blew up my inlet and it was quite a project to replace the line.

[Denis100]

Ice give good result but recently I disolve diswasher soap in hot water and then pour it in the toilet with some gallons of water and it give me good result too.

[blues46]

That is an old boater's trick that always worked well for me. Fill her up, hit some bumpy waves (roads), and flush with hot water!

[JeanM]

Originally Posted by Kegan

My black tank indicator was showing nearly full after emptying. My dilemma was it really empty (as I thought it was) or was something jammed up in the hose that was preventing discharge? Not wanting to do any exploratory surgery on the black tank, I was perplexed. And then I was given this tip ..... dump a few pounds of ice down the commode and go for a drive. I was told that sometimes a piece of TP may get hung on the sensor creating a condition where the tank seems full when it is not. The above tip worked for me. The ice jostled the sensor gremlin..... hope it helps.

Caution with RV's that have macerating toilets - does the ice ruin the toilet macerator? Does the ice get stuck (or melt) on its way through the long tube that connects the toilet to the black tank?

My combo grey/black tank frequently says it's full just after it's been emptied... I've always attributed this to either foam (wrong kind of dish detergent being used, or something used in the shower) or the tank being emptied without first having been truly full. Happy Camper tank treatment + a high ratio of water to anything else flowing through the system = a happy tank

[rowiebowie]

Originally Posted by JeanM

Caution with RV's that have macerating toilets - does the ice ruin the toilet macerator? Does the ice get stuck (or melt) on its way through the long tube that connects the toilet to the black tank?

Good catch. Yes, the ice method is not for macerator toilets. The macerator blades would likely be destroyed. In the off chance they survived (which is unlikely) they would turn the ice into slush which defeats the intended purpose of having floating chunks of ice sloshing in your black tank.

[mumkin]

Originally Posted by Kegan

My black tank indicator was showing nearly full after emptying.

That is the norm. The only time the black tank gauge in any of my rigs showed empty was before they had been used. Those of us who have the inside the tank sensors really needn't ever bother to even look at that gauge because it is pretty useless.

Back in 2004 with my first van, I tried all of those tricks... geo method... ice cubes... and the next time the tank was filled and emptied, again it would still say filled. I even followed my father's RV toilet rule that anything that enters the tank must have passed through your mouth. Thus no TP ever. It still would never show empty. So... why bother? I have better things to do than spend half of the day trying to make a lousy gauge system work. I quickly learned to know when the tank was full, and if it mattered, I could always peek into the tank with a flashlight. Basically I just dump after every trip... or on long trips when I have the opportunity to do so. Empty... fill once with water... and empty again.

Enough...

I always used Happy Camper and if you go to their website, they have good practical advice for care of a black tank. Though ours on a Class B are so small that one must keep that in mind. It is great for controlling smells in both the black and gray tank.

[Kegan]

Originally Posted by JeanM

Caution with RV's that have macerating toilets - does the ice ruin the toilet macerator? Does the ice get stuck (or melt) on its way through the long tube that connects the toilet to the black tank?

My combo grey/black tank frequently says it's full just after it's been emptied... I've always attributed this to either foam (wrong kind of dish detergent being used, or something used in the shower) or the tank being emptied without first having been truly full. Happy Camper tank treatment + a high ratio of water to anything else flowing through the system = a happy tank

As I understand the tip, you don't run the ice thru the macerator. You add the ice, promptly drive around to slosh any 'solids' that might be interfering with the sensor or whatnot and once the ice has melted, dump as normal. Good to hear that the sensor issue is a common one.

[Davydd]

Originally Posted by JeanM

Caution with RV's that have macerating toilets - does the ice ruin the toilet macerator? Does the ice get stuck (or melt) on its way through the long tube that connects the toilet to the black tank?

My combo grey/black tank frequently says it's full just after it's been emptied... I've always attributed this to either foam (wrong kind of dish detergent being used, or something used in the shower) or the tank being emptied without first having been truly full. Happy Camper tank treatment + a high ratio of water to anything else flowing through the system = a happy tank

It is unclear to me whether you are mentioning the macerator from the black tank to the dump or the macerator toilet as in upflow toilets. The upflow toilet send solids all ground up in a slurry so there is no need to put ice cubes in the black tank to loosen or bust them up. You can't anyway. An upflow macerating toilet has a trap just like a home toilet and in mine the black tank is several feet remote from the toilet. Ice cubes are meant to go directly dumped in a gravity toilet black tank below the toilet. Then you drive first before dumping whether with a 3" gravity slinky or a 1-1/2" hose and macerator. Most likely driving all day to be effective the ice cubes would have melted anyway. And anyway, I think it is an old wive's tale to put ice cubes in a black tank. They are not going to break down solids and if you are diligent after dumping you should put water in your black tank and put in chemicals to break down solids and for odor control if you want.

I don't think a macerating upflow toilet needs chemicals anymore than your home sewer.