Monitor says OPn or Err?

[archeogal2]

I know that tank monitors are notoriously faulty. Ours on our GWV Promaster 2015 has been fairly good to date. But in the past week it insists on saying for the black water tank, which I emptied about a week ago: ERR, or more often OPn. The later must mean open. But what is open, and how to fix this? The other monitors seem to be working normally.

[avanti]

Originally Posted by archeogal2

I know that tank monitors are notoriously faulty. Ours on our GWV Promaster 2015 has been fairly good to date. But in the past week it insists on saying for the black water tank, which I emptied about a week ago: ERR, or more often OPn. The later must mean open. But what is open, and how to fix this? The other monitors seem to be working normally.

I assume you have a See-level system. If so:
"OPn" means that there is an open circuit in the sensor loop. This means that you likely have a wiring problem between the sensor strip stuck to the outside of the tank and the control panel. Start by checking the screw terminals on the back of the panel. You should hope that that is the problem. If it is at the sensor side, you may have a project on your hands, since accessing the black tank can be a challenge.

[DaveBad]

I had a OPn error displaying sporadically when I selected my See-level LPG gauge. Turns out there was a badly corroded ground wire connection. Once I repaired it everything worked fine.