sisyphus

Is it absolutely necessary to install a check valve on a sump pump? thanks

GregC

Yes, this will prevent the water from coming back into the sump pump crock, and anything else from coming down the pipe back into your crock.

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GregC, President/Founder [COLOR="Blue"]www.Quicktoolbeltsystem.com[/COLOR]

Speedbump

Without the check valve, the pump will empty the pit, shut off and the water will come back into the pit and repeat the above over and over again.

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FAQ's

Redwood

Sure, you can leave out the check valve...
If you don't mind pumping the same water twice...

Actually I had a job recently where I removed the check valve after installing one. The outlet was lower than the pump and I found that the pump would start a siphon that would completely drain the pit after the sump pump stut off. No check was needed there...

Blue Jay

I only have a 3" head on my sump pump drain so I don't worry about the small amount of water that comes back down into the sump. Don't have to worry about an air lock either.