Getting water hammer with both turning on and off the shower water

Users who are viewing this thread

Blue Oaks

Member
Messages
46
Reaction score
11
Points
8
Location
Morgan Hill CA
Looking for some advice here. I've got some short bangs in the wall when I turn on the shower too fast or turn it off too fast. It happens when I turn the faucet in the bathroom on or off too fast as well, on both hot and cold settings. All the reading I've done indicates water hammer happens while closing a valve, but mine clearly does it while opening as well. Water pressure is less than 40 PSI.

I got good advice when I put my water tanks up on the hill for gravity feed, and I'm hoping for some more here!
 

Jeff H Young

In the Trades
Messages
9,792
Reaction score
2,473
Points
113
Location
92346
Blue Oaks piping likely not properly strapped removing water savers in shower head exasperates the hammer too.
 

Breplum

Licensed plumbing contractor
Messages
2,229
Reaction score
945
Points
113
Location
San Francisco Bay Area
There can be a bang when a valve is turned off, and that would be just normal hydraulic shock noise, referred to as water hammer. Perfect strapping has no impact on the shock noise.
What we often used to refer to as water hammer can also be sequential banging, usually caused by some internal component interfacing like a loose washer in a valve going into a flutter.
 

Blue Oaks

Member
Messages
46
Reaction score
11
Points
8
Location
Morgan Hill CA
Thanks guys. I've been here six years and I think it started about a year ago. I'm hoping I can avoid tearing into the sheetrock.
 

Jeff H Young

In the Trades
Messages
9,792
Reaction score
2,473
Points
113
Location
92346
water hammer can and does often occur when quickly opening a valve not limited to closing.
I have found improper strapping can play a part in causing noise

Like I said if you have removed the water savers and /or have a very open high flowing head or valve it will contribute more to a noise . you may want to try to describe the sound better. a single bang is what I was thinking of or maybe 2 or 3 but not like a machine gun sound . that type of sound is more closely caused by a loose washer .
Which type of valve do you have? old 2 or 3 handle? single handle older standard , or a newer pressure balanced.
Ever had a problem with debris in pipe small gravel etc? they can lodge in a fitting causing a restriction and pressure drop leading to a bang.
BTW. I think its premature to start opening walls as well.
I'd say if you happen to have a cheap water saving shower head that's been unmodified screw that on give it a try . investigate the loose washer idea as well breplum suggested its a different sound from what I'd expect but try it.
Good Luck these are somethings to think of there are many opinions and ideas we've only scratched the surface
 

Blue Oaks

Member
Messages
46
Reaction score
11
Points
8
Location
Morgan Hill CA
The fixtures, including the shower are all one handle. None made the noise when I moved in 6 years ago. The sounds are one or two knocks/bangs, but no rapid fire or repeating sounds of that nature. My showerhead has been drilled out with a 1/2" drill to increase flow, but again I think that was done prior to any sounds emerging.

@breplum are you anywhere near South San Jose / Morgan Hill? I'd gladly pay you to come take a look at it.
 

Jeff H Young

In the Trades
Messages
9,792
Reaction score
2,473
Points
113
Location
92346
drilling out the flow restrictor I think could contribute to your issue just try any cheap low flow shower head see if it makes a difference .
 
Top