[Porky Pig]

I have had similar problems with mine ... mostly with the black tank.

The monitor says it is empty until the tank contents approach the top of the tank ... then the monitor will indicate the tank is 1/8 or 1/4 full. When the tank contents begin to come up the connecting pipe to the toilet ... the monitor will then indicate the tank is full. Sort of like an "ON/OFF" switch ... no in between at all.

Jim Parrett at the factory was kind enough to send me a new "calibrated" unit ... it cured the bad readings I was getting on the LP tanks ... but the black tank problem remained the same. So I did the recalibration thingy.

The first two efforts failed to recalibrate at all ... the monitor panel stayed in the recalibrate mode. Each time I started with 5 gallons of water in the black tank as my "empty tank" ... then filled it full ... then got the calibration error.

The third time I started with NO water in the empty tank ... filled it up ... and got a "successful" calibration. Or so I thought.

It still acts as an ON/OFF switch ... I can't tell when the tank is 1/2 full or 3/4 full ....I give up.

Grey Water, Fresh Water, and LP seem to be accurate. I have no idea if the battery indicators are true or not ... I'm plugged in all the time.

Perhaps the sensor on the black tank is faulty?