Diehard
In Remembrance
Of course a weep hole would not be required if conditions never allowed the sump water level to go so low as to allow air to enter the pumps volute area. Although I would think upon startup there could be a slim chance it could get enough air in there to require more water be added in the sump to force itself into the pump.I never have on those pumps. Only if I installed something else would I check in booklet to see if it was needed. Put in
quite a few pumps with no problems not having weep hole. I knocked on wood because there is that first time.
EDIT: There is at least one manufacture of sump pumps that doesn't require a weep hole, as it designed so the water enters the impeller from the top.