Comment Re:Boom. (Score 1) 325
I wish I knew. I think it's very inefficient, using more city water than the amount of ground water it displaces, but I'm not sure. It's also not very fast. Really, though, the only times it's gone off (that I know of, anyway) have been a few times when I've purposely set it off for a bit while fiddling around with the floaty switch for the main pump.
The whole reason I went for such an exotic backup is that I got stung twice in rapid succession by a combination of 1) *old* gummed up main pump seizing up + 2) marine backup battery exhausting itself + 3) *bad* newly-installed floaty switch. The circumstances were even weirder in that the first flooding incident wasn't even ground water coming up - it was water-heater water going down into my basement after the heater's thermostat, being old and encrusted, reported falsely low, causing the heater to overheat, causing the pressure release valve to give way; unfortunately, its associated outlet pipe wasn't man enough for the deluge, so the water found another way to make gravity happy and went around and out into the basement. The bad floaty switch and dead backup battery came a few weeks later, and I was so paranoid about batteries after that, I felt better plunking down the several hundred dollars for the non-battery option.