Black tank sensor fixes itself: cure or remission?

On our RV, the fresh, grey and black tanks have external sensors that work the way an electronic stud sensor does. When the water in the tank is in proximity of the sensor, the control panel displays the reading. I would think that this should be standard by now as the old contact type are unreliable. Even in the fresh water tank on my old rig was inaccurate because some water sources have less mineral content causing false readings. Unfortunately, the circuit in my control panel for the black tank failed and always reads empty. Rather than replace the unit or attempt repair of the circuit board, I just shine a flashlight down the toilet that sits just above the holding tank. A friend has a fifth-wheel that is only a couple of years old and he is always having to fiddle with the black tank to get readings. I think it is nuts to have to buy bags of ice cubes and drive around a bit to clean the sensors. The external flush connection is useless. I have yet to find a tank additive that is effective either.

DutchmenSport wrote:

rockhillmanor wrote:
When you dump if you fill it back up with water and dump again each every time you dump the sensors WILL work all the time. The second fill up of plain water cleans out any paper/poop stuck to the sensors.

It's what I do and My sensors work all the time.:C

The only problem with this is, if you dump at the dump station because you do not have full hook-ups, you're going to have multiple RV.net forum members behind you complaining you are taking too long at the dump station. To fill the tank a second time and then dump it again, well, you've just added another 20 minutes or more to your stop at the dump station. (I'm just saying???) Full hook-up sites, yes you can spend the time to refill the holding tank, no problem. But at dump stations, you don't have the luxury of this much time.

If you are on a seasonal site, filling the tank a second time is about the only way to clean the sensors, unless you have a toilet wand or a black-tank flusher installed.

Nope, no where's near 20 minutes extra.
I'm outta there in no time! :B

I use the bathroom sink, faucets both wide open to fill black tank. Fills up that black tank real fast!

And actually in my experience I find it a rare occasion to have a long line of RV's behind you at a dump station. Unless you are in a park on a holiday and it's Sunday after noon when everyone is trying to beat feet out to get back home! :W

Thanks all. So much to learn.

rockhillmanor wrote:
When you dump if you fill it back up with water and dump again each every time you dump the sensors WILL work all the time. The second fill up of plain water cleans out any paper/poop stuck to the sensors.

It's what I do and My sensors work all the time.:C

The only problem with this is, if you dump at the dump station because you do not have full hook-ups, you're going to have multiple RV.net forum members behind you complaining you are taking too long at the dump station. To fill the tank a second time and then dump it again, well, you've just added another 20 minutes or more to your stop at the dump station. (I'm just saying???) Full hook-up sites, yes you can spend the time to refill the holding tank, no problem. But at dump stations, you don't have the luxury of this much time.

If you are on a seasonal site, filling the tank a second time is about the only way to clean the sensors, unless you have a toilet wand or a black-tank flusher installed.

I stopped relying on our sensors. I just wait until there is a burp when I flush the toilet. That is the tell tale sign that the tank is almost full. The tank will take a few more gallons after the first burp.

-Michael

When you dump if you fill it back up with water and dump again each every time you dump the sensors WILL work all the time. The second fill up of plain water cleans out any paper/poop stuck to the sensors.

It's what I do and My sensors work all the time.:C

2/3 reading at empty, no big deal. So long as it doesn't get stuck at Full, you're go to go, literally until it says full. Been there done that.

More than likely, you dumped your tanks, but then there as still a bit of water left, or else you added a bit and then drove to your next destination. By leaving 3 or 4 gallons in the tank and driving, everything sloshed and pulverized everything when driving, thus water blasting the sensors and removing whatever was caught on the sensors.

If you dump your tanks before traveling every time and then add 3 to 5 gallons of water with a bit of laundry soap or Dawn Dishwashing liquid, the sloshing of the water and the soap will keep your sensors clean. But if you don't dump and travel with "stuff" in your black tank, you run the risk of crud getting caught, getting pulverized off, and then getting caught again. So if you drain the tank first before traveling, there's nothing to catch on the sensors except pulverizing water and soap, cleaning off anything that could potentially get caught on them.

Did you change your diet...?

Seriously, it happens all the time. Like others said, small bits of TP can trigger false readings...It gets sloshed off or falls off the sensor and you get correct readings again..

Check out SeeLevel tank monitor systems.

Dusty