I won't have a saw here in time to port this weekend, which is a good thing. We had >5" of water in our basement right after Christmas. Our primary sump pump was on the blink and we were running on the backup. I've since bought a second Zoeller M137 pump to make the new primary and wellwill move old M137 to backup. The old backup was another 1/2 HP Zoeller but of much less capacity. It simply couldn't keep up. Either one of these M137s should be able to handle it. While I'm at it I'm going to run new electric to it so that they're on separate circuits.