Black and Gray tank gauges

[dagray]

The guages for my black and gray tanks only work sometimes. I believe their must be a short in them somewhere. I can drain the tanks and the guages show empty. I put nothing in the tanks and a few minutes later the tanks will show full. A few minutes later they show empty again. If I turn the water heater on they may or may not show full. Later I look and it will show empty. It has done this from the day I got it and is getting worse. When I took it to Winnebago under warranty they just flushed the tanks and said that was the problem. I think it is haunted.

[edj]

The tank gauges are just about always totally unreliable. Sometimes flushing the black tank will make it work for a while, sometimes not. The problem is crud on the sides of the tank where the sensors are. The bottom line is that you can not count on the gauge being even reasonably accurate. The best method of dealing with it is to get a feel for how long it takes for you under your usage pattern to fill the tank(s). Then based on that, drain the tanks. Remember, you only should drain the tanks when they are at least half full. If you drain when they are less than that, you risk creating the dreaded "black pyramid" in your black tank.

[Batman_777]

Black tank level check: Turn off water, open toilet, place broomstick handle in...

There are replacement stick-on sensor pads that have good reviews. Some are mentioned on this web-site posts.

["007"]

The See Level system is a good system some have put in, if you can find sensors that will work with system you have they may work.
Some have used Calgon in tanks to clean the insides.

[paz]

The gray and black tank sensors are notoriously inaccurate due to crud and debris. One of the first things I did when we got our current motorhome was to install the SeeLevel sensors that 007 mentions. Not only is the reading reliable, it gives levels in 3 or 5% increments.

Batman gives a humorous solution for checking the black tank level with a broomstick, but it isn't that far off a method that I used successfully in our old travel trailer for several years. In most RVs, you can use a flashlight to look down the toilet and see the water level below. With a little experience, you get pretty good at estimating the amount of space left by eye.