After reading all the problems folks have with their black tank sensors not working properly—me included—I decided to tackle this problem.
Here’s what I did for the black tank:
• Bought anti flush wand from Amazon
Then I cut off the tip to give it a wider spray pattern
• Empty the black tank completely
• Attach the wand to a separate hose coming off the supply line with a “Y” connector, and brought that hose through the bedroom window. The reason I mention this is, is because the wand comes with an adapter to hook up to the bathroom sink. Problem is, when you hook it up to the sink and then open the toilet to insert the wand down into the tank, the toilet is also releasing water and there just isn’t enough water pressure getting to the wand to get the job done.
Having the DW assist me at the water supply valve, I insert the wand down into the toilet connected to a separate hose, turned on water and blasted the water from the wand down in the black tank. Continued a back and forth, rotating motion along with pointing the want towards the end of the tank to blast off residue on the inside walls of the tank where the sensors are mounted on the outside of the tank. Did this procedure for about 3-5 minutes. Then dumped the black tank again. Blasted the entire inside of the tank again, while focusing mostly on the side where the sensors are. Dumped tank again.
• Went to control panel and checked level….yep…shows EMPTY like it’s suppose to.
• Added about 2 gallons of water, 1 scoop of Happy Campers…good to go. I have perform this procedure every couple of months though no matter how I maintain it. The sensors are just not that good, but with a periodical cleaning like I've described, they'll work for awhile.
• I've also tried Happy Camper Extreme in my gray tank didn't work. Then tried 6 gallons of white vinegar and hot water. With both techniques, we drove around some, let sit for several hours. Neither one worked. For the gray tank we've just learned when to dump.
• We've explored replacing with SeaLevel System sensors but not willing to pay the money for the product or the hassle of install for 2 bathrooms and the other systems they monitor.