# Water hammer on well pump issue



## Martinf (Jun 12, 2021)

Hi all,
First a confession: I'm a plumber wannabe...ran all the plumbing for my house and well pump, etc...but I'm a carpenter, by trade.

Before asking the question that I hope you guys can help me out with, here's a little description.

Ive got a 300 ft well with a 5 gpm output that feeds an underground 2000 gallon poly tank. The well pump is controlled by a float switch. All good.

There's a submersible pump in the holding tank that feeds the house. 50' run of 1" pvc to the house basement. Immediately inside the basement is a tee, one side feeds a big pressure tank and the other side is supply to all the house lines. Pressure switch is on the 4' of line between the tee and pressure tank.

My issue is water hammer when the pump cycles. Not really a specific pipe banging a wall kind of hammer, but more a whole system resonating the sudden stop and start of the submersible pump out in the underground tank.

the few times I've had to drain the system for repairs or modification, ive noticed how quiet it cycles...for awhile! But, then in a day or so its back to hammering on pump cycles. I assume this is because draining the system introduces dead air pockets which cushion the hammering? But the the air pockets go away.

I dont have any hammering sound from any valve operation anywhere in the house...just on the pump cycles.

Will installing a hammer arrestor help? And I assume I need a bigger whole house arrestor, not the smaller ones that go at a specific appliance or valve.

And, where should it go? I'm thinking I should put it out at the submersible pump in the holding tank. That would be easy to do right at the union where the galv. steel pipe comes up above the water inside the tank.

thanks in advance for any advice. I sure appreciate it!


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## skoronesa (Oct 27, 2015)

Martinf said:


> Hi all,
> First a confession: I'm a plumber wannabe...ran all the plumbing for my house and well pump, etc...but I'm a carpenter, by trade.
> ...............


This site is for Plumbers only. Go find a DIY site to ask.


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## sparky (Jan 8, 2014)

Martinf said:


> Hi all,
> First a confession: I'm a plumber wannabe...ran all the plumbing for my house and well pump, etc...but I'm a carpenter, by trade.
> 
> Before asking the question that I hope you guys can help me out with, here's a little description.
> ...


Fill the bladder tank to 150psi it doesn't have enough pressure in the bladder to stop water hammer,it has to overcome the pump pressure for it to be able to stop pump water hammer


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## Martinf (Jun 12, 2021)

sparky said:


> Fill the bladder tank to 150psi it doesn't have enough pressure in the bladder to stop water hammer,it has to overcome the pump pressure for it to be able to stop pump water hammer


I've gotten lots of good advice over the years from a variety of trades forums...and helped folks in turn. It's too bad the club handshake is so important here.

And, thanks for the dangerous advice but, naw, I think I'll keep my pressure tank a few psi below the cutout.


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## skoronesa (Oct 27, 2015)

Martinf said:


> ............It's too bad the club handshake is so important here.
> ...............


For what it's worth, a club handshake from sparky is pretty cheap.

Enjoy the new hammer Mr. Carpenter


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## sparky (Jan 8, 2014)

skoronesa said:


> For what it's worth, a club handshake from sparky is pretty cheap.
> 
> Enjoy the new hammer Mr. Carpenter


Bahahahahaha


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