Water Hammer?

[amazin6]

Hello all, we moved into a 15 year old house one year ago. It is single level stucco masonry home without a basement. Never had any water pipe noises prior to this. We developed a leaking bath tub faucet. It is a Moen type and I bought a new cartridge from Home Depot. I tried to remove the old one and it was not coming out without a fight. We ended up using a plumber to change it. He braced himself against tub and finally got it out. We soon developed a water hammer. Called plumber back as well as emailed him and no response. I had lawn guy go into attic as wife says no more roofs or attics for me. He said no access to pipe as finished attic floor. Called another guy and he cut hole in closet behind tub to create access panel to mixing valve as well as anchor any loose pipe. All pipes were secure so wasted effort and money.
I tried shutting off main, opening all faucets, closing all faucets, main back on.
I tried shutting off main, opening all faucets, main back on, closing all faucets.
I tried a toilet water hammer arrestor on back of toilet in this bath and no help.
I thought the exertion to remove tub cartridge started this but pipe is secure.

Now I am flummoxed.

I do have a water softener, whole house water filter, hot water tank in garage that I did not do anything to while trying shut off trick. Should I?

Could it be the mixing valve?

Would a hot water heater expansion tank help as there is none now?

There is not much copper plumbing pipe visible anywhere in this home except at water heater in the garage.

Any ideas for a novice would be welcomed and appreciated.

All the best to all of you

 

[Mr_David]

I do have a water softener, whole house water filter, hot water tank in garage that I did not do anything to while trying shut off trick. Should I? Can't think of any

Could it be the mixing valve? Maybe

Would a hot water heater expansion tank help as there is none now? Probably not

Looks like you tried a few thing before you popped the question.

When does the hammer occur? a single bang or a rattle?
Only when you turn off or use the currently repaired valve?
Does it occur when using any other fixture in house?


Is it a Pull on/push off Moen valve?
Or does it turn counter clockwise from off to cold to hot?(Positemp)


Check your water pressure with a gauge at a hose bib. Test gauge $11 @ HD

 

[gendow]

Ideally every fixture should have a water hammer arrestor. Since the shower valve now has an access panel on the back wall, I would suggest starting there and installing hammer arrestors on both the hot and cold water supplies. I'm trying to attach a pic but my photobucket not working. I'll try again later.

 

[gendow]

Shower valve with hammer arrestors;

 

[gendow]

Laundry with arrestors, you get the idea;

 

[Mr_David]

I edited my first post..
. You can add air chambers to the hot and cold supplies

But you didn't have that problem before the repair. So that may not solve the problem but only mask it.

 

[amazin6]

Thanks for so many ideas.
The Moen valve is one that turns.
Pipes rattle when turning off water.
Hammer happens when using other bath now too.
I may try the washer arrestors first as I should be able to do those.

Thanks again to all.

 

[amazin6]

Solved!!

I went back to Home Depot where I purchased the original new Moen cartridge and found my knowledgeable salesperson who sold it to me. I began to explain the issues and he stopped me and said "Buy another cartridge as I had the same problem with a new cartridge too."

Bingo! No more water hammer.

Well at least now I have water hammer arrestors on washing machine, on toilet, a new access panel behind shower in closet and my lawn guy knows what my attic space looks like but no longer any water hammer!!!!!!!!!!!
Thanks to all.

 

[Mr_David]

Solved!!

.

WOW! good to know.

That should have been our first bit of advise.
Being that replacing the cartridge was when the problem started.

I have never encountered that before with a Moen Positemp.
But I can see how a defective one might cause that.

Inside the cartridge is a stainless steel cylinder called the balance spool.
It's function is to slide inside the cartridges to balance flow of hot/cold incoming water.
If not working properly it can rattle or shift causing a water hammer.
Usually they get stuck and you end up with not getting any hot water.