# Silencer check value, still clunks



## Boston Plumber (Apr 12, 2008)

Richo...Higher is better here.

I would install that check valve on the 7 foot vertical run near the top (but not AT the top!!)

That should reduce the banging you hear.

Let us know what you think.


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## Richo (Dec 6, 2007)

I will give that a try tomorrow and see how it works out.

Thanks


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## Richo (Dec 6, 2007)

Follow up: After moving the silencer check valve toward the top of the vertical discharge pipe (about 1 foot down from the top) the clunk is actually even louder. I don't think the check valve itself is louder in this location, it's just that previously is was below the sump cover is now it is exposed and closer to the main floor.

The silencer must have a ball inside it because the clunk sound is like a ball bouncing where you hear 3 clunks, each subsequent one being softer than the previous. The sound is coming directly from the "silencer" check value, ironically.

Are there sump pumps that have internal check valves in them? All I can think is that maybe that is the case and the sump pump's check valve is competing with the silencer and there is not enough back flow force to allow the silencer to do its job. The reason I wonder about this is that prior to installing the silencer, my sump pump did not have an external check valve and it always made a clunking sound regardless.

What do you think?


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## Richo (Dec 6, 2007)

I guess I didn't look close enough at the sump pump originally. There *was* a flapper check valve screwed in to the discharge at the base of the pump. I took it out and the silencer still clunks just as bad. Ah well....


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## Boston Plumber (Apr 12, 2008)

I am sorry Richo....

I did not notice the word SILENCER in your post. Is this a special check valve...? 

I just posted 2 pictures.....these are the only 2 types of check valves I have ever used on sump pumps or sewage ejector systems...any chance one of them looks like yours?

Any chance you can post a pic. or a link to the type you have...??

I am thinking you should swap over to the type I show in pictures..??

Let me know what you think.

Thanks


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## Richo (Dec 6, 2007)

The silencer is a model of check valve made by Pasco specifically meant to silence the sump pump clunk.










I did contact Pasco about this and they're sending me another one for free in case mine is defective. That's great customer service.

I'll have to wait and see if the new one makes any difference.

Thanks for your reply.


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## Boston Plumber (Apr 12, 2008)

Hey..keep us posted, OK??

If that does not do the job, then I will recommend that white check valve I posted in my last post....never had a cluncking complaint using this type!!

Good luck.


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## preflyt (Jul 15, 2008)

*The Silencer White With Red Check Valve*

iI had a loud ejortor pump in our house for the last 6 months.

My friend is a plumber and he came over with the silencer. It has two check valves.

It is white with red screw tighten rings. 

He installed it in the middle of the pvc tubing

He installed it and you cannot even here the pump come on or off anymore.

Our son loves it because he lives in the basement. 

It only cost $41.00

Install it you wiill not be disapointed:thumbup:


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## preflyt (Jul 15, 2008)

*The Silencer*

HERE IS THE PDF FILE FOR THE SILENCER:
http://www.pascospecialty.com/images/new_items_0806/new_items_0806.pdf


The model I have is 29142

you cannot even here the pump come on or shut off. No more hammering 
:thumbup:


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## tryanythingonce (Feb 20, 2009)

Richo, 
I didn't see where there was a follow up on the "silencer" from Pasco. Was the first check valve defective or did the replacement one still hammer too? I am interested in purchasing one and wanted to know if it was worth the extra cash.


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## Richo (Dec 6, 2007)

Hi,

The second silencer didn't make a difference. It was the same as the other one so apparently it wasn't defective, but not effective either.

I haven't tried anything else yet but I may look into the white one BostonPlumber recommended or the #29142 silencer when spring comes and the sump pump is running more often.


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## Bob Mariani (Dec 1, 2008)

Boston Plumber said:


> Hey..keep us posted, OK??
> 
> If that does not do the job, then I will recommend that white check valve I posted in my last post....never had a clunking complaint using this type!!
> 
> Good luck.


I have the white one you posted. It clunks and shakes and then gurgles for a little while. I saw a post stating that a small hole should be drilled at the lower end of the PVC inside the tank to let the water trapped in the pipe before the check valve drain. This relieves the pressure which may be causing the noise. I have not fixed mine yet so I am asked your opinion on this "hole requirement"


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## CraigV (May 4, 2009)

A couple of points:

1. The check valve is intended to prevent the water column from draining back through the pump and refilling the sump after the pump shuts off. If there's enough water involved, the pump will cycle back on again, either immediately after shutoff, or more quickly than before, since the sump capacity is essentially reduced by the amount of water you're cycling back and forth.

2. Installing the check valve further up the pipe, as suggested in several posts, will result in the water below the valve draining back to the sump. This will make some noise, and again, reduces the capacity of the sump, with the result being the pump cycling on more often, or immediately after each pumpout.

3. Drilling a small hole in the pipe just above the pump allows the pipe to prime when first installed or after service, or if the sump pit is normally dry for some part of the year, and then fills after a storm. It simply breaks the air column pressure. The small leakage during pump operation isn't a problem, and it also will not have any effect, positive or negative, on the check valve operation or noise.

4. Check valves with a swing gate, such as for sewage ejectors, should be installed vertically. Horizontal installation, or anything below about 45 degrees can result in solids becoming stuck in the flapper and jamming the valve open.

5. Don't attempt to install anything other than full-flow (most often swing gate) check valves in ejector pump systems. Again, the risk of solids being caught in the valve increases exponentially with the amount of obstruction the valve presents to flow.


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## Richo (Dec 6, 2007)

Interesting. Thanks.

My "Silencer" seems to be clunking louder than it originally did. I was considering the white one but after Bob's post, that may not be the answer either.


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## Squeakyhinge (Jan 29, 2011)

BUT why does the sump clunk if it didn't do it before (when it was newer than 2 seasons). I missed the poimt where this was established. Is it a failing check valve? Do check valves wear out? What causes them to wear out after just a couple seasons? Has there been mention of one which would last longer?


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