# Water Hammer



## Atomic Bearcat (Aug 9, 2013)

I can't figure out where it's coming from or why. This is in my own home, and I've checked the usual suspects. PRV is good, and set at 50psi (confirmed with pressure gauge). Expansion tank isn't water-logged and has 50 psi as well.

The house is 12 years old. I didn't do the rough-in, only the finish work.

I don't want to start throwing parts at the problem. I realize that I could put in a couple of water hammer arrestors on the hot & cold trunk lines, but I think that's just a "Band-Aid". The only fixtures that seem to be the problem are the ballcocks in 2 toilets (one directly below the other). They are both Kohler Wellworth and still have the original Fluidmaster 400A in them.

Could it be as simple as replacing the ballcocks with say, a Korky? 

Discuss, and flame on.


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## PlungerJockey (Feb 19, 2010)

How fast do they fill. I've repaired water hammer issues at toilets by simply opening the supply stop more.


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## Atomic Bearcat (Aug 9, 2013)

Angle stops are open 100%. :huh:


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## PLUMBER_BILL (Oct 23, 2009)

Atomic Bearcat said:


> I can't figure out where it's coming from or why. This is in my own home, and I've checked the usual suspects. PRV is good, and set at 50psi (confirmed with pressure gauge). Expansion tank isn't water-logged and has 50 psi as well. <snip>
> 
> *Prove that the toilets are the cause. Turn them off -- hammer stop?*
> *If so change the F/M washers, still there how about the stops if brass craft or older Wolverines the washer that pushes over the little knob could be the culprit. However when the toilets are shut off and noise is still present could be anything. Could be that the cause was always there but a thermal expansion kept it under control ... now that tank is waterlogged so no more cushion. Let us know what you find! Did you measure thermal tank air when the pressure was off?*


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## vinpadalino (Aug 27, 2010)

Sounds like the fill valves on the toilets. I've had that complaint a couple of times.


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## Atomic Bearcat (Aug 9, 2013)

vinpadalino said:


> Sounds like the fill valves on the toilets. I've had that complaint a couple of times.


I know you from somewhere. Hvac Talk? HPF? You might know me under a different screen name.


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## Atomic Bearcat (Aug 9, 2013)

To answer a couple of questions:

Angle stops are Wolverine Brass 1/4 turn.

I shut off toilets. Water hammer is still present while the clothes washer is operating.

I am going to replace both fill valves this weekend and see what happens.


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## dclarke (Dec 22, 2012)

What's the piping material ? I've had a bad fill valve vibrate the floor in a house.


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## Bayside500 (May 16, 2009)

Atomic Bearcat said:


> To answer a couple of questions:
> 
> Angle stops are Wolverine Brass 1/4 turn.
> 
> ...


install hammer arrestors on WM bibs, it is code of for us


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## PlumberDave (Jan 4, 2009)

First is it just one bang? Like a quick electro-mechanical valve on your washer, dishwasher or ice maker? Or a rapid banging. Like a machine gun?


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## PlungerJockey (Feb 19, 2010)

Atomic Bearcat said:


> Angle stops are open 100%. :huh:


Sounds like you nedd to change some fill valves and supply lines:thumbsup:


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## Atomic Bearcat (Aug 9, 2013)

Update:

Installed Korky 528's and new braided supply lines in both toilets in question. Water hammer has disappeared when the valves close.

I'm going to install hammer arrestors on the washing machine bib, as Bayside500 suggested. Interesting that's code in some places, but not here.

@dclarke. All copper in the house. No PEX anywhere.


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## vinpadalino (Aug 27, 2010)

Atomic Bearcat said:


> I know you from somewhere. Hvac Talk? HPF? You might know me under a different screen name.


Yes sir Hvac talk. I haven't been on there in a while.


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## Will (Jun 6, 2010)

Sioux Chef makes some good hammer arrestors that you can install on a stop. Put those on the Water Closets, dishwasher, and ice maker. Also put hammer arrestors on the washing machine. Here we have to put them on the water heater also, hot side and cold so you could do that also.


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## dclarke (Dec 22, 2012)

I was figuring it was all copper. We have lots and lots of CPVC in my area.


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