sump line flowing backward?

[klutch]

I recently Y'ed off my sump line and put ball valves on it so when my yard gets saturated during heavy rains I can switch over to an alternate line. The second line has a 20' hose on it so I can move it around and dump it into a different location. This is more of an emergency thing so during heavy rain I can divert the water elsewhere manually. Well everything works great but with that long of a line whenever the water is pumped out and the pump turns off it sucks all the water that is left in the line back down into the sump pit. Needless to say it is quite a bit of water. It does this with the other line as well but it's quite shorter and the water isn't nearly as much. Anything I can do to prevent this? I imagine I need some sort of vent to displace the water with air so what is left over in the line can flow on out. Any thoughts?

Thanks in advance.

[CraigFL]

Most sump pump systems I know of have a check valve right above the pump so this can't happen. You should check to be sure you have a working one. Cheap to replace!

[klutch]

Most sump pump systems I know of have a check valve right above the pump so this can't happen. You should check to be sure you have a working one. Cheap to replace!

Thanks CraigFL, from a similar(ish) thread I found I also see there should be a hole around that check valve. Would having that valve without the proper hole prevent it from working correctly. From reading I wasn't sure what a check valve was but I'm guessing it's another term for backflow valve maybe?

[CraigFL]

I not sure why the hole but if you think of the valve as a flapper type , water would push the flapper up and away when the pump was on and water flowing. As soon as the flow stops, the flap seals down over the hole and doesn't allow the water to go back into the sump. Sometimes a ball is used instead of a flapper but the action is similar.

[Juice]

I think the hole you are talking about is called a weep hole. This hole sometimes comes installed on the pump itself or when you install it you would drill about an 1/8in. hole in the pipe near the top of the pump. This hole just prevents the pump from becoming air locked. It would not help from water coming back through the pump when it shuts off. Adding a check valve within a few feet of pump should solve your problem.

[klutch]

Thanks for the help guys. After looking at the sump I don't appear to have a check valve in place. My line immediately makes a 90 degree bend after it gets over the floor and then another 90 up the wall. Does it matter where the check valve is located in the line? I'm sure closer to the pump the better but I don't know how I could cut the PVC down in the well to put something in line.