OVERTALK
Not Bad
Further thought:
I wonder whether Hydro_aire, during their pump redesign process, ignored the phenomenon of conductive silver sulfide build-ups, placed the pos and neg terminal strips too close together and they're consequently being bridged electrically and causing the pumps to run continuously. Whatever the mechanism, it has to be something that's allowing the pumps to both heat up electrically and then "run on" once dry (and also then heating further frictionally due to being overheated). That might make more sense as these pumps are supposedly "fixed" (or replacement) ones - i.e. without the original wire-shorting problems.
The suspicion of Hydro-Aire probably having repositioned positive and negative terminals stems from the root cause of the original shorting problem (too much wiring in close proximity).