Our crawl space gets water in it all the time. I think I have determined that what is happening is that water from the ditch where the sump pump drains is backing up the pipe into the sump pump and back into the crawl space. I've dug the ditch deeper, but because of clay we can only go so far. I can't re-route the discharge pipe. Someone told me that a check valve is what I need and they said I would need to dig back about 2 feet from where it empties into the ditch and install the valve, but that the valve would be bigger than the 1 1/2 discharge pipe. I found a valve to fit the pipe, but wonder why I have to go back that far from the ditch? Also, if there is that much water in the ditch, is the sump pump action going to be strong enough to keep the water flowing the way I want? The man in the hardware store said I had to drill a hole in the discharge pipe to keep the pump from air locking. The pipe is buried, so would drilling a hole help?

The check valve should be installed where it would be accessible for repair, could be installed at the pipes end, I don't know what you could possibly achieve by putting a hole in the pipe. The only thing that may be a question is if the pump can overcome the operation of the check valve( spring pressure) Good luck, Mike

Why we must install check valve at the discharge line?

Hi Rizaluna...

We install check valves with SUMP PUMPS to keep the water that got pumped up and out by the pump from falling back into the pump pit/basin. Without the check valve in place the pumped water can fall back into the pit/basin and create a cycling of the water that can burn the pump out.

Hope that answered the question for you...

Mark



PS: For future readers be sure to drill a 3/16" hole...angled downward... in the discharge pipe at the level of the top of the pump itself to prevent airlock between the pump and the check valve. Rare as it is, a pump without this hole can "dry pump" and cause the pump to burn out and fail.