# water hammer on well pump



## MD plumber

I went out on a call this morning for a complaint of water hammer. It happens every time the pump cuts off I beleve it is caused by a bad check on the pump but wanted to get some feed back on here.


----------



## plbgbiz

Is it a single hit hammer or multiple hit (like a machine gun)?


----------



## plbgbiz

Submersed pump?

Check valve at the pump or integral to the pump?

What is the evidence of the water hammer? Noise? Pipe moving or shaking?

Where is the hammering heard? Near the well? At the pressure tank? Somewhere else in the house?

Have you checked the pressure tank? I would think it should be absorbing any shock from the pump cutting in and out.


----------



## Redwood

plbgbiz said:


> Have you checked the pressure tank? I would think it should be absorbing any shock from the pump cutting in and out.


1st thing I'd check...


----------



## vinpadalino

I've seen that before. I had to add a model 30 expansion tank domestic. I installed it before the tank T. That was the end of that problem.


----------



## MD plumber

It is a submersed pump the noise is heard at the wall where the line enters the house. The noise is a single hit and no pipes are moving. I never thought to check the tank to see if it was water logged. The Home owner said it has been on going for a few months now and has always been a single hit. I have ran in to many water logged tanks and never have had this happen.


----------



## Richard Hilliard

I am thinking the pressure tank is inside the basement and not outside and the pipe is from the pitless adapter? Do an electrical test on the pump to make sure the pump is working properly. 
 If the tank was water logged the pump would turn on and off while water is being used. (Machine gun sound) 
Check air in the pressure tank and make sure it is correct.


----------



## MD plumber

Richard Hilliard said:


> I am thinking the pressure tank is inside the basement and not outside and the pipe is from the pitless adapter? Do an electrical test on the pump to make sure the pump is working properly.
> If the tank was water logged the pump would turn on and off while water is being used. (Machine gun sound)
> Check air in the pressure tank and make sure it is correct.


The system has a good draw down the pump it not kicking on and off. Yes the pressure tank is in the basement and the home owner checked the pressure I have delt with him before and he knows how to do that at least. The pump is 21 years old the home owner wants to just replace it anyhow but I want to make sure the water hammer goes away.


----------



## Protech

What size is the pump riser and the service to the bladder tank? Is it hammering from the pump cutting in or out and sending a pressure wave down the service? If that was the case the tank would act as a speaker and the hammer would be really loud.

Any chance of cutting in a gauge on the service?

The only to things I can think of are high velocity in the service or a hard seat on a check valve.


----------



## MD plumber

The pipe is 1" from the well to the tank. The hammer happens when the pump shuts off and the sound is coming from where the pipe enters the house. There is about a 50' pipe run from where the pipe enters the house to the tank. And there is no sound at the tank.


----------



## Protech

what type of pipe and what's the pump HP?

Any check valves other than the foot valve on the pump? If so, where are they?


----------



## MD plumber

3/4hp pump black well poly from pump to the pitless and from the pitless to the house. PVC from the wall 50' to the pressure tank with a check valve at the tank.


----------



## vinpadalino

MD plumber said:


> The pipe is 1" from the well to the tank. The hammer happens when the pump shuts off and the sound is coming from where the pipe enters the house. There is about a 50' pipe run from where the pipe enters the house to the tank. And there is no sound at the tank.


50' is far. Put model 30 domestic expansion tank were pipe enters the house.


----------



## Richard Hilliard

The water hammer has recently started. I am betting the amp draw is affecting the shutdown of the pump creating more torque. He wants a new pump put it in and watch the noise disappear.


----------



## MD plumber

Richard Hilliard said:


> The water hammer has recently started. I am betting the amp draw is affecting the shutdown of the pump creating more torque. He wants a new pump put it in and watch the noise disappear.


Thats what I'm thinking also I was just double checking myself to make sure I take care of the problem the 1st time..


----------



## Richard Hilliard

Why is there a check valve at the pressure tank? I am sorry I missed the check valve statement. Pump should have a check valve in line above pump ,used to have to install it seperately now they come with the pump.

I still believe it is the amp draw. 


When I see a check valve installed at the pressure tank it makes me believe there is a leak in the pump piping in the casing or from the pitless to the home.In ohio we used pitless adapters all the time. Here in Florida most of the Florida plumbers I have met have no idea what it is or what a torgue arrestor is.


----------



## MD plumber

It's pretty common to see check valves installed at the tank around here. I don’t use one there on my installs because I really don't see a need for one there with one at the pump. Is there not a lot of well systems in florida and if so how do they make the transition from the well casing to the line that runs to the house?


----------



## LEAD INGOT

MD plumber said:


> The system has a good draw down the pump it not kicking on and off. Yes the pressure tank is in the basement and the home owner checked the pressure I have delt with him before and he knows how to do that at least. The pump is 21 years old the home owner wants to just replace it anyhow but I want to make sure the water hammer goes away.


 Did he isolate the tank and take house pressure off the tank before checking the pressure through the snifter?


----------



## MD plumber

Yes


----------



## LEAD INGOT

Ahh, I'd say clogged foot valve, or the pump is taking a dump.


----------



## Richard Hilliard

They come out of the top of the casing with a 4x1 1/4 x 1/2(common size)
well cap. The first number is the diameter of the casing,second water pipe size and third is wire

When I first moved here the majority of pumps were set 7-20 feet deep . In less than 20 years most of the wells the pumps are set 100 feet or better.

Wells closer to the gulf have been compromised due to water usage and the salt water is leaching into the wells.

A lot of well points used back in the day here. A lot of packer jets used here too.
In ohio we used to set them 100-300 feet deep depending on the quality of the water.


----------



## bchplumbing

*Water hammer on well.*

Here in Missouri, most of our wells are deep. Mine is 320' deep. Don't know what to tell you on the water hammer with out being there.


----------



## MD plumber

I replaced the pump yesterday and that took care of it.


----------

