Sump Pump Check Valve Clattering

[prbart140]

I installed a new sump pump & check valve in my existing sump basin & drain line located in my crawl space last fall. The previous sump pump was not working reliably & the old check valve's rubber body was literally broken in half!! The new installation works well with one exception: when the sump pump shuts off, a series of loud hammering sounds, gradually decreasing in volume, will occur for 3-5 seconds before finally stopping. This sound is very annoying as the pump is located under a bedroom & disrupts sleep when the pump is working frequently. My old check valve did not have this problem. Any ideas on how to quiet down this situation would be appreciated.

P. Bartosek
Aurora, IL

[DUNBAR PLUMBER]

It might be the design of the check valve you purchased that is causing this issue.


By the way,


Did you drill a 3/16" hole between the check valve and the top of that pump in the discharge pipe?

[prbart140]

No I didn't drill such a hole, but I intend to when the weather starts to warm up!! Do you think that performing that operation will eliminate my noise problem?

[gleese]

I have exactly the same problem...the check valve hammering after the pump shuts off.
I have installed the check valve directly onto the base of the pump, then a piece of flexible hose, then the solid pipe to the outside through the foundation wall.

Should the check valve be further up the run away from the pump?

Could it be the flexible hose? Should I use solid hose?

Will the 3/16" hole solve this problem?

Where exactly should the hole be drilled? Not clear on location.

Thanks so much!

[Wgoodrich]

The closer to the outside drain elevation you install you check valve the less clatter will occur. That is the good news. The 3/16 hole is a weep hole allowing the water from the check valve back to the pump to drain back into the sump pit.

Now a problem exists. The further you install the check valve up the line from the pump the more water flows back to be repumped next time the pump cycles on thus causing that rest time to shorten between cycles.

You want to install you check valve in a location being a happy medium as close to the outlet elevation as you can without causing too much water to flow back through that 3/16 hole back into the sump pit to be repumped.

Now that should be clear as mudd ! Hee Hee

Wg