Black Water Gauge

[Blacktail]

We just got home from camping and emptied the holding tanks but the black tank gauge still says its full? I know it is empty i could feel and hear the water going out. Any thoughts on this???

Thanks

[Festus2]

Tank gauges, especially the black water one, are notorious for giving false readings. This is largely due to build up of "crud" (toilet paper and other nice things) around the tank sensors. If you have a black tank flush, try flushing the tank out and see if the reading shows an empty tank.
After dumping your tanks, you should add a bit of water and some chemicals or whatever you use to keep the tank "fresh". Try adding a bucket or two afterwards to keep any residue from drying out and sticking to the sensors.

[phillyg]

What Festus said. Plus, I've had many rv's and have never, NEVER, been able to get really accurate readings on any tanks, especially black tanks. Residue keeps building up on the sensors rendering them virtually useless.

[badge4]

I take my tank flush wand and connect it to the hot water connection for the clothes washer in the bathroom closet and I blast the tank the best I can a few times a year. This seems to help but still get false readings every once in awhile. The best tip is to get into a routine of dumping the tank on a regular basis and don't even worry about the gauges.

[BigCajun]

I've heard that you can fill your tank approximately 1/4 full and add a couple of bags of ice down the toilet. Then take the rig on a bumpy ride swishing the tank around. The ice helps break up the stuck on debris.:bdance:

[Outbackmel]

Same issue on my 2011; Outback 5er. I flush my system on a regular basis and use the system tank sprayer. Know the tank is empty. Finally gave up on trying to read the darned thing with the guage. On our next trip, I am going to try the "ice" in the tank; slosh it around; solution. No great expectation of success.

Like comment above, when I pull the lever; it's like water flowing over a waterfall :)

Some things you learn to live with...;)

[mikell]

Put Calgon water softerner in the tank to keep the sticky stuff from stickin

[rjsurfer]

Think of the black, grey and galley indicators as an interesting light show....not very informative but cute to look at.

Don't obsess about them.

Ron W.

[ktmracer]

We just got home from camping and emptied the holding tanks but the black tank gauge still says its full? I know it is empty i could feel and hear the water going out. Any thoughts on this???

Thanks

If youwant working probes the easiest solution is horst mericle probes for the black tank. The replace the existing probes

[Jeffrey11]

Tank gauges, especially the black water one, are notorious for giving false readings. This is largely due to build up of "crud" (toilet paper and other nice things) around the tank sensors. If you have a black tank flush, try flushing the tank out and see if the reading shows an empty tank.
After dumping your tanks, you should add a bit of water and some chemicals or whatever you use to keep the tank "fresh". Try adding a bucket or two afterwards to keep any residue from drying out and sticking to the sensors.

Try 1/4 cup of laundry detergent each time you empty the tank. Close valve poor in detergent, use it keeps the tank cleaner. Always use flush system if you have one two before heading home.

[edw_jr]

Glad to hear about the tank sensor problems; thought it might be just me. (joke) Mine worked fine for the first couple months and haven't been right since. Guess one just has to live with it and dump before the good stuff backs up. Nothing I have tried to clean the sensors has been very successful, but if anyone has a new idea I would love to hear it.

Happy Camping! And don't let your tanks get to ya.

[mespro]

I was worried because I din't have the guages in my new Cougar 33RES, but now I think it is a blessing in disquise, I'll quit worrying.

[mobile42]

Every once in a while I use the "GEO Method" and works for me especially using Calgon Water Softener for a slippery side inside the tank. I also don't dump my black and Gray tanks until I get home (I use my house sewer clean out) so when I'm driving I'm usually carrying back a half to 3/4 full tank to cause a sloshing effect from the water in the tank plus all the solids are broken down.


http://www.wheelingit.us/2012/03/21/rv-tank-sensors-the-geo-method/

[unclerj]

Best thing we've found is two bags of ice with half box of baking soda and half cup of laundry detergent. Add 10 gallons of water and go for a drive.

We've even done this after we had flushed with the black tank wash system and you wouldn't believe the extra crud that got cleaned out.

[mikell]

When adding whatever you do to your tanks take into consideration the distance from the tank to the valve. You might need to add enough water to fill the area before adding your special mix.

[tech740]

One thing that I have found that hasn't failed me yet is adding cheap dish soap and a little extra time. I add a quarter cup of dish soap in the black tank when we set up. I don't dump till it's full to capitalize on the whooshing effect. When I dump it I fill the tank a couple extra times and add soap each time. After the third time it is usually clean and reading zero. For the grey tank I add about a half cup of automatic dishwasher soap to the tank. I use the cheapest soaps I can find because they go quick. But the 5 bucks is worth not guessing.
I learned both of these tricks on this forum. Great place with great people.

[JRTJH]

Here is a picture of the probes. There are 4 in each tank. Anything that hangs on the probe will provide a "source to ground" and cause the tank monitor to read that sensor. If it's the top sensor (probe) the tank will read full even if it's empty.

It's pretty easy to imagine a piece of toilet paper "sloshing" around and getting hung on every one of the black tank sensors. Sometimes ice, dish soap, rinsing and other "gallant efforts" will dislodge the TP, other times, it may be easier and less frustrating to just stop pushing the buttons on the monitor.