Gray and Black holding tanks in Winnebago

[rpchap50]

I have a 2005 Winnebago Adventure 38J  motorhome. About 4 weeks ago my gray water holding tank level indicator started showing 3/4 full all the time. I have owned this motorhome since October 2019 and the level indicator has always worked correctly. The indicator showed the tank being empty after being dumped , then shows higher levels as the tank filled. I have cleaned the gray water tank out using all the normal techniques (dish washing liquid, strong cleaners, etc, then driving many miles)  but nothing has worked and the gray water tank indicator continues to  show the tank as being 3/4 full. Then 6 days ago, the black hold tank indicator started showing 3/4 all the time as well.

I will add that when the gray water holding tank get full, the full light (red) come on and when i dump the tank, it goes back to 3/4 full.  I have never had the black water holding tank get full so I don't know for sure the full light (red) works. 

As I understand it, Winnebago uses proximity switches outside the tank to indicate the level, which means nothing on the inside the tank to get clogged up. There is a calibration technique for the sensor electronics, but i have not tried that yet.  I have checked and all the proximity switches on the outside of the tanks are in place and tightly affixed to the tank. 

I am new to RVing do i am looking for any help or guidance you are able to provide. 

Does anyone else experienced this type of issue previously?

if so, what did it take to correct this?

Richard 

[ianbullock]

When you dump your black tank, first of a are you dumping it when it's full and secondly are you priming with several gallons of water and adding at least 2, 8 oz bottles of Thetford Aqua Kem or Campa Chem? One should be added to the rear toilet and one to the powder room toilet.

[rpchap50]

Ian, Thanks for  the feedback,

I normally dump the black tank when it is 1/3 to 1/2 full and the gray tank is full. I dump the black tank first, then the gray tank to flush the sewer hose. Then i flush the toilet 3-4 time with full bowls of water. I have been using Campa Chem. I only have the one bathroom. 

[kaypsmith]

If you can get to them, try cleaning the wires and wire terminals to the proximity switches  with an electrical contact cleaner and then replace them one at a time. Most RV's with this type switches use ground at the tank to activate the switch, and water on the wire connection can give a false reading.

[ianbullock]

14 minutes ago, rpchap50 said:

Ian, Thanks for  the feedback,

I normally dump the black tank when it is 1/3 to 1/2 full and the gray tank is full. I dump the black tank first, then the gray tank to flush the sewer hose. Then i flush the toilet 3-4 time with full bowls of water. I have been using Campa Chem. I only have the one bathroom. 

Your black tanks should only be dumped when it is 3/4 full or more. Preferably full. Dumping it with only half or less will leave sediment in your tank.  

If I was you I would fill both the black and grey tank full, add 2 bottles of Thetford Camp Chem to each, let sit for 3 days then empty. Black tank first.

[five]

As noted, dump the black tank when full.  The key to the sewer system is lots and lots of water.  That's all you need, the chemicals serve to make money for their manufacturers, but are not needed if the sewer system if installed correctly and used correctly.

[manholt]

We use a liquid dish soap, like Dawn, Palmolive, etc. a 1/4 cup to a gallon of water and flush through system each month, into black and grey tank, fill both up and dump!  In the days between, we back flush after each dump!  99% of all RV grey/black systems are basically the same, no matter how fancy the potty is!  Also, as long as there is water in the "P" traps and the vent is operating properly, you will not get any odors...I agree with FIVE.

On our last coach, American Tradition, we had the same problem as you.  Our indicators was thru tank and gave false readings, we put in the Seaborne system, solved that.  

[txtiger]

Even if your tank indicators are attached to the outside of the holding tank, they can get a false reading from stains on the tank. Cleaning your tank with dishwashing soap can help clean the inside of the tank and prevent stains building up on the tank walls. Another problem which Customer Service at Winnabego told me is that the sensors are glued onto the outside of the tank and often come partially unattached. Check to see that the sensors are firmly attached to the outside of your tank. 

[rpchap50]

Thanks for all the feedback and comments. Will continue to work to find a solution using your comments and advise what the fix is. 

[manholt]

Keep in touch!  Stay safe,