Exterior Tank Sensors

[MinnieKJB]

Why does my grey tank read 2/3 full all the time? I have given the tank a good cleaning 3 times. I have a 2018 vista 29ve and the sensors are on the outside of the tanks. All the others work fine. Its driving me nuts. When I bought this thing they said that you wont have a problem with these sensors giving you a false reading because they are stuck on the outside of the tank. Any thoughts on what could be wrong or what to do. Thanks

[thompwil]

The sensors are a capacitive type (electronics term). I installed hundreds of the industrial type in factories. Problem happens when enough build up occurs on the inside of the tank to trigger the sensors. The sensors on our rigs are not adjustable like the industrial types, and I couldn't find an adjustment on the readout either.

I significantly reduced the problem by reducing the capacitive coupling. I carefully removed the sensors and cleaned off the sticky stuff. I then installed two layers of 3-M double stick tape to the entire surface of the sensor to make the interface thicker, then reinstalled the sensors. Tank levels are working fine, and I rarely get a false reading anymore. If at those rare times it does happen, it clears itself in a half hour or so after dumping the tanks.

I’ve been considering applying three layers of the tape to see if that corrects the problem entirely, but it’s working well enough that I just haven’t got around to it yet.

[MinnieKJB]

Originally Posted by thompwil

The sensors are a capacitive type (electronics term). I installed hundreds of the industrial type in factories. Problem happens when enough build up occurs on the inside of the tank to trigger the sensors. The sensors on our rigs are not adjustable like the industrial types, and I couldn't find an adjustment on the readout either.

I significantly reduced the problem by reducing the capacitive coupling. I carefully removed the sensors and cleaned off the sticky stuff. I then installed two layers of 3-M double stick tape to the entire surface of the sensor to make the interface thicker, then reinstalled the sensors. Tank levels are working fine, and I rarely get a false reading anymore. If at those rare times it does happen, it clears itself in a half hour or so after dumping the tanks.

I’ve been considering applying three layers of the tape to see if that corrects the problem entirely, but it’s working well enough that I just haven’t got around to it yet.

I don’t quite understand what all that means but I will try and get to my sensors and take them off and add that 3M tape to them and see if that works thanks for the info. Not sure how they would still read the tank now that the sensors would be thicker with tape

[Morich]

This can be true at times but be aware that there are also times when other things like bad boards get involved.
I have not dealt with it directly as a personal problem but I have swapped thinking with quite a number of forum users who have chased it down with Winnebago and found there were different series/builds on the boards sued, some red, some green and swapping the board was their cure.
Seems to be a problem that when it works, it works good for a long time, I have had three different Rv with this type sensors and none have given trouble and we rarely do anything at all for the tanks other than using the off the shelf chemicals. It is such a "non-issue" that I have no idea what brand chemical we use, just that it is not liquid because we had a spill of that type one time.
But when they are a problem, it seems they can be a problem, regardless of any "magic" formula or process used to maintain the tanks. My brother currently has one of THOSE!