[DennisB]

We have had our trailmanor for a little over a year now and have had a continuous problem with the gray tank sensors being stuck on 2/3 full even after
Completely dumping the tank. I repeatedly dumped and flushed the tank with various commercial tank cleaners…no luck. Last spring, Scott at “Custom Rv” kindly replaced the sensors and after a few weeks the same problem occurred even though we were very careful what we put in the gray water tank. I read it is a very common problem and learned that most Rv people just learn to live with it.
So I kind of surrendered.
Then last week, I read an article that recommended 1/4 cup calgon water softener and 1/2 cup borax laundry detergent. We were leaving on a trip a few days ago so I poured the two ingredients down the sink drain and filled the gray tank until it was 2/3 full. We drove for 2.5 hours and at our first stop of the trip it read 1/3 full after dumping. I repeated the dosage the nex morning and drove for about 3.5 hours. On dumping, the tank read “Empty” for the first time in a long time. Since then, the sensors have been working fine.
This information may be helpful to others