Liberty
10-09-2003, 01:06 PM
I just purchased SP-500 Ridgid sump pump to replace my old one. Previously, the existing sump pump manual recommended a vent hole on the discharge pipe just above the pump but below the check valve to prevent any air lock. I did not see anything about this for the new sump pump. In fact the new sump pump manual recommends a reverse check valve directly attached to the pump. What is the reson for this?