Got it with the sensor issues... I don't trust them either. Here's the deal though. We actually RAN OUT of water this weekend. It just stopped and the sensors did show that it was out. Now, after having the city water supply hooked up and I did not refill the tank as you normally would, the sensor shows the fresh water tank at 2/3. I turned off the city water, disconnected it completely and turned on the electric water pump.... there is water running again. Still don't get how the fresh water tank would get partially filled by hooking up to city water supply....