tank sensors

[highfeather]

Hi I'm new here, 2017 Winnebago Fuse has been pretty much a dream and everything has worked or been made to work (had the fridge control panel replaced under warranty). I've made plenty of trips, 13K miles in 18 months) and the tank sensors have always worked. Just got back from boondoocking where I started with my fresh water tank full. I was pretty conservative with water use over 3 days and the gauge showed 2/3 full when I pulled out and went to the dump station. I think, but don't really remember, that the sensors were registering a reading on both the black and gray tanks. I dumped, flushed and headed home. I still had 2/3 of the fresh tank so decided to just run it down the sinks, shower and toilet until it all emptied into the holding tanks which I would then empty onto a thirsty tree. I got the water all out of the lines and into position on a downslope towards the tree I planned to water. I checked the panel to see about how much I had in black and gray and they both read empty. Odd since I had just flushed 2/3 of the fresh water tank down and into those tanks. I emptied the black first and some clear water, but not much came out; no big whoosh like I was expecting. I then emptied the gray and a LOT more came out.
Two questions: first what could be the problem with the sensors not registering for the holding tanks? And what would be the solution?
second I ran a LOT of water into the toilet yet little came out of the black tank so is the toilet the ONLY thing that goes to the black tank and everything else goes to gray?

I tried searching the forums for this and didn't find anything.

 

[BCam]

Tank sensors are notorious for not being right, the black water sensor being the worst offender. Fortunately it's easy enough to just look down the toilet to see if it's empty.

Since you have a pretty new rig, it may have external rather than internal sensors which are supposed to be more reliable but are still susceptible to malfunction due to waste build up in strategic spots.

Here's a link that may help:

https://www.guaranty.com/blog/rv-tank-sensors

 

[Tucsontoy]

You have it right, only the toilet goes in the black and everything less is in the gray. That 3" black line can drop a lot of clear water in a few seconds, The level indicators are just a reference and not exact. Just remember what you saw and remember it as a reference.

 

[LarryW-WO]

If anything should be improved it’s tank sensors.

 

[Jaeger-WO]

We just finished our first trip in a new Minnie and the tank sensors were one of only two issues that surfaced during our trip. I've seen one other thread that bemoans the lack of accuracy for the factory sensors and in that thread, the SeeLevel sensor system was said to work well but be expensive. I just checked and it appears to be about $200. But in that thread, the consensus was that with experience, you "just know" when you're running out of water or tank space. The one common thread was to just look down into the black tank to see how it's doing.


FWIW

Jim

 

[LarryW-WO]

jaeger, its usually my grey tank that fills first, so I put dish water down the toilet.

 

[thompwil]

I wasn't expecting as much trouble with the external sensors as we are having either. The tech support person from Winnebago suggested filling the tanks halfway or better then adding a good dose of liquid dishwasher soap. The first time it worked perfectly after driving a few hundred miles that day then draining the tanks. Not long afterward the problem returned and now the cleaning process isn't getting any results. I'm formulating plan "B" at the moment...

 

[LarryW-WO]

Thomp, they just don’t work...industrywide.

 

[thompwil]

Thomp, they just don’t work...industrywide.

That seems to be the case. It is sad though because the technology works when applied properly. I used capacitive level sensors in industrial control applications for many years with reliable results. Of course the sensors were much better with sensitivity adjustments.

The sensitivity needs to be adjusted to compensate for the coating inside the tanks. But,,,, there is no adjustment available as far as I can tell. I wish I could get my hands on a schematic of the controller board. Or maybe get a few industrial sensors, but I can't verify compatibility without schematics. Oh Well

 

[LarryW-WO]

Similar to knowing the cog you are in when cycling, thomp. Ride enough and you just know.

 

[BCam]

If your sensors are inside the tank, here's a video on cleaning the gray water sensors, it's worth a try. There's also a link to a video on sensor adjustment in the text of the page, but I don't know if the panel Winnebago uses can be adjusted as well.

How To Clean an RV Gray Tank & Sensors - TheRVgeeks

 

[thompwil]

Similar to knowing the cog you are in when cycling, thomp. Ride enough and you just know.

Haha Yes. I know what you mean, we've been RVing with self contained units for over 30 years. The old tank sensors with the probes inside the tanks were the worst. You get a feel for these things for sure

I'm just a compulsive tinkerer/fixer I like my stuff to work right, plus it keeps me off the streets.

 

[Walt523]

You have it right, only the toilet goes in the black and everything less is in the gray.

Not true, some coaches the washing machine goes into the black tank. Our coach the black gets the washing machine. About 6 loads will fill up our black tank.

The only plus to this is I get to clean out the black tank more often.

 

[Swiss RV]

Tank sensors problem solved....

On front, sorry for my English, but my motherlanguage is german and swissgerman.

We have a Tour 42QD model 2011 and had Problems with false reading the first day on all 3 tanks.
The problem is the following:
All sensors are what they call capacitive sensors, same princip as in a car with automatic rain sensors.
As soon as rain comes on the windshield or freshwater, greywater or blackwater into the plastic tank as slowly get filled up, the capacity of the sensor will change.
This realize the electronic and say 1/4 - 1/2 - 3/4 or full depense how much liquid in a tank.
The sensors are mounted with a very thin doubleside tape outside at the walls of the tanks.
As soon as water etc. get into the tank, the sensor react.
Even the tank is only f.e. 1/4 full, during driving ist splashing against the walls and give false Alarm.
Problem with Grey- and Blackwatertanks is, that the dirt with water stays at the walls and give continuelsly false Alarm.
If you park for a while ist drying the wall and the Alarms Comes down.

I solve this problem very simple :
Buyed from 3M a Grey doubleside tape with red cover for outside use.

Peeled the sensors off, cleaned both side, tank and sensor, placed the tape at the sensor, cutted around and brought it back to the wall.
Because the sensor is farer away from the tankwall it makes him less sensitive but as the tank filled the sensor will read it.
Since then, all sensors working fine.
Maybe you have to use 2 layers of tape. Test it out.
Myone worked with 1 layer of tape.

I informed Winnebago already in 2012 about my solution but no Response...….

Dont hesitate to contact me.

Marc

 

[Tucsontoy]

Walt, the OP was about a Fuse, Not a class A.

 

[Chiefig]

Hi I'm new here, 2017 Winnebago Fuse has been pretty much a dream and everything has worked or been made to work (had the fridge control panel replaced under warranty). I've made plenty of trips, 13K miles in 18 months) and the tank sensors have always worked. Just got back from boondoocking where I started with my fresh water tank full. I was pretty conservative with water use over 3 days and the gauge showed 2/3 full when I pulled out and went to the dump station. I think, but don't really remember, that the sensors were registering a reading on both the black and gray tanks. I dumped, flushed and headed home. I still had 2/3 of the fresh tank so decided to just run it down the sinks, shower and toilet until it all emptied into the holding tanks which I would then empty onto a thirsty tree. I got the water all out of the lines and into position on a downslope towards the tree I planned to water. I checked the panel to see about how much I had in black and gray and they both read empty. Odd since I had just flushed 2/3 of the fresh water tank down and into those tanks. I emptied the black first and some clear water, but not much came out; no big whoosh like I was expecting. I then emptied the gray and a LOT more came out.
Two questions: first what could be the problem with the sensors not registering for the holding tanks? And what would be the solution?
second I ran a LOT of water into the toilet yet little came out of the black tank so is the toilet the ONLY thing that goes to the black tank and everything else goes to gray?

I tried searching the forums for this and didn't find anything.

If you dumped it on Tuesday, it probably will not be full for 3,4,5 days anyway, dump again.

 

[jerichorick]

Ah yes. Tank sensors AGAINIIII



The Winnebago sensors on the later models are pretty reliable IF you can keep the crud off the sides of the tank. We have finally found a way of doing just that.


For the black tank we use a cheap, enzyme containing, power dishwasher detergent. (Tanks are my job.) I use a coffee mug full of the power dissolved in hot water. This goes down the hopper after the tank has been emptied and Sani-flushed. I make certain that there is enough water in the tank to slosh around as I drive. So, do this on your last dump before hitting the road. It does no harm to add solution again after your next dump. But most of the work is done as you drive. A cup full of dissolved backing soda helps reduce odors.


For the grey. We leave the grey opened when hooked up. We avoid dumping grease and most lumpy stuff down the drain. I close the gray off a day before dumping the black and use that water to flush out the dump hose after a black dump.


Have been doing this method for years. The only time I have a gauge problem is when I forget to do the pretrip prep to the tank. A few times out after that and we are back in business.


Happy trails all.
Rick

 

[thompwil]

...
I solve this problem very simple :
Buyed from 3M a Grey doubleside tape with red cover for outside use.

Peeled the sensors off, cleaned both side, tank and sensor, placed the tape at the sensor, cutted around and brought it back to the wall.
Because the sensor is farer away from the tankwall it makes him less sensitive but as the tank filled the sensor will read it.
Since then, all sensors working fine.
Maybe you have to use 2 layers of tape. Test it out.
Myone worked with 1 layer of tape.


Marc

That makes sense, I'm going to give it a try

Thanks !

 

[BCam]

Since all tanks are of different thicknesses, materials, etc. there must be a relatively easy way of adjusting the sensitivity of capacitive sensors. The sensitivity would also change as the tanks age and build up coatings inside.

I'd suggest researching the make and model of your sensors for more info. I saw one video that showed simple adjustment screws on the panel:

 

[thompwil]

I pulled my monitor out to see if there were any adjustments on the back. None to be found anywhere. That would make it way too easy.