fishgate
Active member
It will only pump out the volume in that chamber and run the risk of burning the pump out, but that's better than a flooded floor.
FYI: Once the return chamber runs "dry" enough water remains to keep the pump cool/lubricated for awhile. I have had pumps run over 24 hours with not enough water to pump any up to the tank when I forgot to top off the sump (before I had an ATO) and never had an issue with them.