Cleaning the Gray water sensors?

rondeb wrote:
I am so careful, but I obviously have got something on the sensors in the Gray water and it was stuck on 2/3. It will register full, but will never go below 2/3. The motorhome is almost new and the tank is truly emptying. I tried putting some Tide in the tank while we traveled, and now the sensor registers 1/3 so I have made progress. Does anyone have an idea as to what I can put in the Gray to clean those sensors. I am assuming they have grease or something of that nature. I wondered about putting some coffee grounds while we travel. Anyone have an idea. My black tank sensors are stuck on 3/4 and NOTHING has worked for those, but I can see into that tank and can visually see the level. The black also empties completely as I can see the bottom of the tank and it is clean as can be when we empty it. We have always used tons of water. Tomorrow I am going to try and put like 3 bags of ice in the black and if that works great, if not, not going to worry about that.
This is our 4th Motorhome and I have never had my sensors not work so it is frustrating.Thanks

Thetford makes a 'great' holding tank sensor cleaner. And it DOES work! I use a bottle of it periodically.

Everyone always seem to blame the sensors themselves. Interestingly I was reading my MH manual about the tanks and sensors and right in the book it says that many different types of minerals in just 'plain ole water' in your fresh tank can foul the sensors. CG waters have a lot of minerals in them! Not to mention all the stuff that sticks to them when you don't flush and clean them.

Here's my routine:
Which after many years my sensors always work. Yup as many say it is only a holding tank. But it is a holding tank with sensors in it that you have to keep the TP and garbage off of them, if you expect them to work.

Black Tank 'Every' time I dump the black tank- I then fill up with water and dump again.

Gray tank - Publix has a quart bottle of lemon cleaner for 1.00. This stuff works great! I put half a bottle in periodically. Once a month when I dump I fill up with water and put a whole bottle in and then dump again.

Fresh water tank - Once a year I put in a bottle of Thetford Fresh water tank sanitizer. In between those times I periodically will rinse out with some bleach if needed.

IMHO, JMHO, you DO have to put an effort in to keep them clean if you want the sensors to work for you. :W