Best way to keep the sensors working is to keep them clean! Use the formaldehyde-free black tank solution, and (if you have one) the black tank flush every time you dump. And close the B/T valve for 1-2 minutes (but no longer) to allow the water to accumulate in your tank. Then rock the trailer from side to side, dump and repeat 3-4 times; until the dump water runs clear. You can also supplement the tank solution with a cup of Calgon water softener or laundry baking soda. You can dump a cup of bleach and some Calgon or baking soda in the sink drains after you dump. As the grey tank(s) fill, the bleach/Calgon/soda will clean off the sensors. After 8-1/2 months of full-timing, my sensors are still working great!
2013 Eagle 266RKS
2011 Ford F-150 w/3.5L Ecoboost & H.D. Tow Package