Well - connection to water hammer in home?

[beowulf]

We have a deep water well with pump down about 400 feet. We have experienced what I would describe as "water hammer" sounds in the house. It is a bit difficult to determine precisely where the sound comes from (seems sort of a general sound - sometimes I think I can hear it at the hot water heater, sometime in walls near one bathroom, but not always). The sounds are definite but a bit subtle - i.e., not a severe banging but clearly annoying - and concerning. After discounting that the house was haunted, I cannot link the periodic thumping to anything else other than the well-pump when it kick on or off. We replaced the pressure tank and the check valve in February. We were experiencing some of the same sounds before those replacements but the sounds continue - and perhaps are a bit more frequent now. Pressure switch is at 40-60.

Other potentially relevant information:

- when the water is drawn down to 40psi (the kick-on point), at that precise point when the pressure reading gauge goes to 40, it then drops immediately to about zero, fluctuates rapidly (sort of bounces a bit below the 40 mark) and then goes to 40 as the pump kicks on. All of that lasts for about one second. That is, the needle does not simply stay at 40 and then steadily climb as it kicks on, but dances a bit first. I don't know if that is normal or symptomatic of some issue.

-the home is about 80-90 feet from the well. The pipes from the well are galvanized pipe and I think 2" dia, and perhaps 18"+ inches under ground and run to the house, with split-offs to a guest house run and for outside bibs. The house run pops up near the house, to a simple filter and then to a 3/4 inch line supply under the house which runs in a crawl space. -when I turn on a faucet in the bathroom I can sometimes hear a barely audible bump - unless you listen for it and are aware it might happen you would never notice it.

I am about to have a well service company come out and evaluate things at the well (e.g., faulty check valve slamming - even though new in February, or whatever), but thought I would first post here - to educate myself before I call - or perhaps avoid the call.

Although the sound seems more general than identified to specific areas (such as in a particular bathroom) I am aware that the sounds of loose pipes can resonate throughout the house a bit and thus I may need to drag and contort my 74 year old self down into the crawl space and drag myself around under there to attach pipe straps here and there (or open up walls to check on the vertical pipes behind showers, etc.) but that is not something I really look forward to doing - I would rather chew on tin foil for a day.

The hammer sounds do not appear to exist at all in the guest apartment building (new in 2009) which is much farther from the well (perhaps 200 feet), and which is supplied by a T off of the well line before it gets to the house, and then runs with 1 1/2 inch PVC, and then goes into the attic area using PEX.

My questions are:

-Is there a water hammer absorption (?) device for wells (i.e., not just one designed for a particular appliance or in-side location) that can be installed in-line that might resolve this - or is such not recommended?

-Any suggestions as to the cause and regarding anything I can do to address this?

Sorry for the long narrative, but I like to provide as much information as possible as I am not certain what might be relevant to a solution. As always, thanks in advance for reading this and for any suggestions. I always greatly appreciate the help I receive here - if you can save this old man from a trip into the very low crawl space, I will buy the beer.

 

[RNeumann]

Water hammer is the normal result of opening and closing valves that control flowing water. The noise obviously isn’t.
The most common cause of the banging pipe sound is a pipe that isn’t properly supported. I’d skip the well service tech and call a plumber.
If you wanted to do a bit of investigation yourself I’d stick my head in the attic while someone else caused the noise (typically turning water on and off). Hopefully it’s louder in the attic and you or someone else can strap or restrap/isolate a pipe.

They do make a gimmicky water hammer arrestor that can be installed near valves. I’ve never seen one installed or installed one myself on a residential project- especially one with a well supplying 40-60psi!!

If the noise started suddenly let’s hope it’s just a strap or support that broke lose in the attic!

 

[oldnslo]

If the gauge is dropping to zero it sounds like the bladder in your pressure tank has lost its pre-charge. Shut the well pump off, open a faucet to fully relieve all of the pressure in your system. Once the water stops flowing check the pre-charge pressure on your pressure tank. Should be a valve stem type connection for checking this pressure. I believe this pressure should be around 2 - PSI below the low set point of your pressure switch or in this case around 38 PSI.

Yes there are water hammer devices. These are typically mounted by the point of use like sinks, washing machines, etc.

Good luck

 

[bcp]

I was having weird gauge and pressure switch activity that I traced to the 1/4 inch galvanized pipes supplying them. They were almost totally clogged with rust, leaving pinhole or less passages that made for delayed reactions. They are now brass.

Bruce

 

[Ford850]

I had severe hammering when our well kicked on. It was traced to the check valve in the main 'in' line from the well, just ahead of the pressure switch and tank. The well company suggested removing it, saying sometimes they slam open and cause that noise. I removed it completely and I have no more hammering noise.
I also had low pressure in my tank which caused the odd gauge drop and jump like you described. Like oldnslo described, I drained the tank and recharged it to 2psi below the cut in (38 psi on a 40-60 system). In my case, I had lost charge due to a bladder leak so I replaced the tank soon after, but the 38 psi pressure holds now and the gauge is steady.

 

[oosik]

If the gauge is dropping to zero it sounds like the bladder in your pressure tank has lost its pre-charge. Shut the well pump off, open a faucet to fully relieve all of the pressure in your system. Once the water stops flowing check the pre-charge pressure on your pressure tank. Should be a valve stem type connection for checking this pressure. I believe this pressure should be around 2 - PSI below the low set point of your pressure switch or in this case around 38 PSI.

This plus check for a loose pipe and strap any found. This most likely will cure the problem.

 

[beowulf]

I’d stick my head in the attic while someone else caused the noise (typically turning water on and off). Hopefully it’s louder in the attic and you or someone else can strap or restrap/isolate a pipe. /QUOTE]


Thanks - no pipes in the attic of main house - unfortunately all in the crawl space with very low clearance - need to crawl on your belly and the only way you can turn face up to the floor is in the spaces between the floor joists. . . but likely that will need to be done and as wife will refuse to do it, that leaves it up to me.

 

[beowulf]

Thanks to all for responding and for the specific advice. I will follow recommendations - starting with checking the pressure in the tank and making sure it is set to 2 lbs below 40 lb cut off point.

Re the removal of the check valve - isn't that needed to prevent water going back down into the well? Not sure - the check valve in my system is plumbed in between the well head and the pressure switch/gauge - from the well head (vertical drop), next is the check valve (horizontal), then next is the pressure switch with gauge attached, and then to a T coupling through which the pumped water can go into the pressure tank, and then be drawn down through that T coupling into the line to the house. The check valve is new - but someone said sometimes something gets stuck in there. . .

Re the q 1/4 inch galvanized pipe for the pressure gauge - you are correct that they get clogged - I found that to be the case when I put a new gauge on - I cleaned it then, but will recheck it again.


After resetting the pressure tank I will wait to see what happens and if I have to go under the house to re-strap pipes. In any event, I will likely wait until weekend to venture under there so someone else will be around to assist with that and make sure I get out, to help feed lighting and pass any tools I might need. etc. Daughter will be here then. And usually, before I venture under the house I toss a couple of foggers down there the day before.

Thanks to all for the advice.

One final follow up question: It is possible I don't have a water hammer issue but just loose pipes? Because the thumps occur even when I don't turn on water in the house, I was assuming a water hammer, but perhaps there is just enough of a pressure change when the well kicks on or off that it causes already loose pipes to thump?

 

[RNeumann]

I’d stick my head in the attic while someone else caused the noise (typically turning water on and off). Hopefully it’s louder in the attic and you or someone else can strap or restrap/isolate a pipe. /QUOTE]


Thanks - no pipes in the attic of main house - unfortunately all in the crawl space with very low clearance - need to crawl on your belly and the only way you can turn face up to the floor is in the spaces between the floor joists. . . but likely that will need to be done and as wife will refuse to do it, that leaves it up to me.

Haha.....who knows where I got attic from your 74yo crawling around comments in the original post!?!?

Same concept with the crawl space- harder to fall through the drywall though!

 

[jaxs]

You didn't make it clear if (A) hammer only occur's when well pump cycles (B) when any faucet in house is opened (C) only certain faucets are opened (D) when certain faucets are closed (E) and most important,if you are able to cause the noise at will. Knowing specifics go a long way in helping you,,,,,,,esp by long distance.