# RV Holding Tank Sensors



## Willy (Jan 11, 2008)

My black and sometimes gray water tank will show 1/3, or half full, even when they are empty. Is this an wiring issue, or a sensor issue, or something else? I dont mind it that much just because I can pretty well tell when they are full if I look closely, but it would be nice if they worked correctly.


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## antigua (Dec 17, 2007)

In my manual, they say there are a few sensors in both the grey and the black holding tanks and sometimes if you use regular toilet paper, it doesn't breakdown like the biodegradable kind and can sometime attach itself to one of the sensors giving you a false reading. I don't know why the grey water would do that unless it's a little sludgy. That might be the problem.


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## ctfortner (Nov 16, 2007)

That is what I have had happen to mine, the paper actually sticking to the sensor area. Now, for the grey water tank, I dont know. Possibly something that went down the drain and is on the sensor??


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## popuptrailercamper (Jan 11, 2008)

Apparently soaps, detergents, grease and oils all affect the grey water sensor. The oils can come from cooking oil residue in a pot and then washing in the sink or oils that you put on your body and shower in the RV.

Over time, this messes up the sensor and it needs to be cleaned out. The problem is grease, oils and residue from soaps does not break down that easily so it hangs it around sticking to stuff and floating around.


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## bill0830 (Nov 16, 2007)

Take a look at the *Black Water Tank Odor *forum. I did a write up on how to take care of the odor issue, which is caused from this issue. Take care of the build up takes care of several issues. Odor, buildup and sensor problems.


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## Willy (Jan 11, 2008)

excellent guys, thanks a lot for the info. Good write up, i printed it off


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## grace (Nov 16, 2007)

That sounds like what our plumber said to us. He was here to snake out the pipes. He said don't put any grease down the sink at all. So we collect it in paper towels and cans instead. Then it stays cleaner and has less odors.


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## billyj (Feb 1, 2008)

Someone told us years ago to put a couple of tablespoons of baking soda when filling the fresh water tank. This will not affect the taste but it goes through the system and also cleans the contacts for the tank misers.


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