Originally Posted by rwgates
I have a 2016 Denali 287RE, I have a question and need help. On my blackwater holding tank when you press the button to check the level, it shows "full" all of the time. Right now it is completely empty but all 4 lights come on indicating it's full. Can anybody help that may have a solution?
First welcome to the Forum, anyone who owns an RV will tell you that the sensors are anything but accurate and maintenance free. I purchased my latest RV used and the previous owner used the toilet as it was meant to be used. My wife and I on the other hand only use it for liquid, all other goes to the campground washrooms, we have had the same issue as you and many others since we owned it.
My first purchase was a clear extension to the drain system so I would watch what was draining out, watching for clear liquid as an indication that I hand rinsed everything out. I tried the on board flushing system (I have a 5re) still the sensor read full, tried multiple additive and enzymes, even the ice and drive around method, still read full, next heard about the Geo method, bought the Calgon and laundry soap and did it for multiple months, no improvement. Last time I was into my local RV store I talked to the parts guy about replacing the sensor with new Horst miracle probes (look them up if you don't what they are) and he recommended that before I went to that level I try a product called "RV Boss Level gauge cleaner for RV black tanks" I though what the hell nothing else has worked. I had a few weeks off the camping circuit so I filled the tank and dumped in the proper amount and left it for three weeks. I had tried this before for this length of time but never with this product in and nothing else worked
. After three weeks with the RV Boss product in it, I drove to my next campsite about an hours drive and dumped on arrival when I dumped it and the water coming out the of black tank was brown, even my wife asked if I had used the toilet for none liquid use. which I hadn't. I ran the built in flushing system and for the first time my gauge now reads empty. I will continue to use this product every time I empty my tanks from now on.
Only time will tell if this continue to read better. Even though remember that the sensor are only so accurate.
Good luck if you try the same product. Oh and I have a couple of container of liquid Calgon to give away if anyone wants to try the Geo method.