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

Try 2 gallons of white vinegar with 10-15 or so gallons of water.Vinegar is cheap so maybe more than 2 might be needed.This worked for our B water tank when it stuck sometime ago.Hoping this helps you out...

If that does not work they say a bag of ice generally will.. I replaced mine with the Horst sensors. No more issues.

Ranger Smith wrote:If that does not work they say a bag of ice generally will.. I replaced mine with the Horst sensors. No more issues.=================== here's a video on the Horst Sensors:Horst SensorHappy trails,

when you add the ice, do not use excessive water in the tank, if you do all the ice will do is bob around in the water. put a little bit of water in so that the ice can slide around and slam into the walls.for the grey tank, I would think water softener and detergent would be about as good as anything.bumpy

For the grey tank I us the grey tank chemical. Never have any problems. For the black tank I made up a wand with valve. 30" of copper pipe with cap on one end & hose fitting & valve on other end. On the cap end drill two 1/4" holes on the side of the cap 180 degrees apart so water comes out to each side at high pressure. I made mine about 30 years ago & it works. Walmart sells one but it doesn't work that well.

Cleaning the Gray water sensors? | Good Sam Community

21 Replies

super_camper
Explorer
May 22, 2013
rondeb wrote:
Well I put 5 gal of vinegar in both the gray and the black and 2 bags of ice in the black and we drove home. Didn't do anything. I so thought that vinegar would work LOL I'm going to let the tanks sit with the 5 gal of vinegar and about 6 gal of water in the tanks and see if anything cleans up.

When we leave in a few months, I'll find some tank cleaners as suggested above.

I use a tank additive called campa-chem from thetford. I don't normally use in the grey tank but I do occasionally add it to a 1/4 tank of clean water before a long drive. The product says is cleans the sensors, I have no idea if this is the reason my sensors still work but I guess it could be...
rondeb
Explorer
May 22, 2013
Well I put 5 gal of vinegar in both the gray and the black and 2 bags of ice in the black and we drove home. Didn't do anything. I so thought that vinegar would work LOL I'm going to let the tanks sit with the 5 gal of vinegar and about 6 gal of water in the tanks and see if anything cleans up.

When we leave in a few months, I'll find some tank cleaners as suggested above.
chevyman2
Explorer
May 20, 2013
Well I used to use a bag of ice in the black tank just before hitting the road. It always worked great. The OP here said he is having problem with Grey tank. I bet ICE would be tough to push down the kitchen sink drain.

I think it was a greay water cleaning agent by "Thetford" that I used a long time ago. It worked. Im just not positive it was a Thetford" product. I would search for a good grey water tank cleaning agent. They should probably all do OK. I would think.
Still_Searchin_
Explorer
May 20, 2013
For those that installed Horst sensors, how much of a job was it? How easy did the old sensors come out, etc. The video is impressive.
rondeb
Explorer
May 20, 2013
Thanks guys. So many good ideas. The idea of the water causing the problem may be my problem. We stayed 5 months In Las Vegas and there isn't harder water anywhere. (That is where the sensors started acting up) I fought hard water stains everywhere. I bet the tank walls (that is why the full still works) have hard water build up. We dump every 2 days, can go 3 with normal use so it isn't crucial to have the sensors work, but I just like to have everything working.

I am definitely going to try the vinegar. That should help the hard water build up.

Thanks a million. I also had no idea that Winnebago put the sensors on the outside so since we keep our tanks clean all the time it has to be hard water sitting in there.
silvercorvette
Explorer
May 19, 2013
I have not tried it yet, but I was told to put about 1/4 to 1/8 of a cup of pine sol in each tank partially filled and let the liquid and pine sol slosh around while you drive.
Clay_L
Explorer
May 19, 2013
The problem is not dirty sensors. The problem is water bearing crud on the tank walls that fools the sensors. Anything that cleans the tank walls may help. The Horst sensors put the sensor out from the tank wall so the crud doesn't touch the sensor and that seems to work pretty well.

I have been full timing for 11 years and have tried all the remedies people say will work and none of them have worked. Weekend users seem to have better luck with them than us full timers do.

I have non-contact sensors on the outside of the tanks (Winnebago went standard with them in 2005 on Class As), but they can be fooled if the walls get crudded up too much. At this point my black tank reads full all of the time and the gray reads 3/4 full and the full LED is the only one that works right.
peaches_cream
Explorer
May 19, 2013
Ranger Smith wrote:
If that does not work they say a bag of ice generally will.. I replaced mine with the Horst sensors. No more issues.

Just wondering, how do you get the "ice" into the gray tank?
rockhillmanor
Explorer II
May 19, 2013
Just be careful with the Dawn! I poured a whole bunch of that stuff down the drain and ended up with FOAM city! The sensors didn't know which end was up for days because of all the foam! And the sewer hose was all foaming for days.

If I run across a restaurant supply house in a town where I am staying I always try to pick up a couple of boxes of no-foam soap the bartenders use in those brush cleaning sinks. You can't use a foaming soap in the brush cleaners or it explodes with foam.

It is a no foam soap AND it contains a disinfectant that works real good in the tanks.
Retired_andLove
Explorer
May 19, 2013
I've found that if I throw a couple of packets of dishwasher detergent in the black water tank with some water and let it slosh around on the way to the campground that my sensors clean right up. I plan to do that with gray water tanks though I have very little trouble with them.