Black water sensors sending false positives.

My 2005 Journey has external proximity sensors on the black water holding tank for detecting the waste water level. These are the black square stick on type with the white + sigh in the center. Like most other types of sensors they are susceptible to sending false positive signals when guck builds up on the inside of the tank. When chemicals, ice, and enzymes don’t do the job, I have the final solution to the problem.

Get a 3-4 ft long garden watering wand with an articulating head and adjustable spray nozzles. The head has to be less than 3 inches in diameter.

Locate the sensors and note their position relative to the toilet. Turn the adjustable nozzle to “Vertical” spray. Connect the wand to a separate garden hose with at least 40 psi of pressure. With the Coach water turned off, the sewer hose connected and the drain valve open, open the toilet valve and put the wand down the opening. You may have to start with the head pointed straight down and push it to a right angle via the bottom of the tank. Aim at the sensors and spray. This works every time for me. While you are there, you can clean the plumbing between the toilet and the tank. I recommend wearing a face shield for this.