Q. We flush our motorhome’s blackwater tank often, but the monitor panel
always shows the tank is full, even when it is actually empty. Is there a trick for getting
the sensors to work properly?
A. Probably the easiest way to help clean
the inside of the tank and the contacts is to dump the tank, then add 10 gallons or so of
fresh water to it. Flush about 20 pounds of ice cubes down the toilet and drive it. If you
drive on a winding road and/or brake heavily, the ice will slosh and help scrub the insides
of the tank. You also can use a holding-tank sensor cleaner, or a spray wand made for the
job. Both are available at RV stores, including Camping World.