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Water Hammer Noise FAQs-2
Q&A on causes water hammer or shock - banging pipes
- POST a QUESTION or COMMENT about banging pipes and water hammer noise: how to find, fix, or prevent banging water pipes or heating pipes
Questions & answers on diagnosing & fixing banging pipes & water hammer noise - hydrostatic shock.
The articles at this website will answer most questions about plumbing noise associated with water hammer or water surge, including the diagnosis and cure of water hammer noises as well as many other building plumbing system inspection or defect topics.
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Banging Sounds: Water Hammer Noise FAQs #2
These questions about water hammer and water hammer noise causes & cures were posted originally
at WATER HAMMER NOISE DIAGNOSE & CURE - be sure to review that article.
On 2017-12-14 by Sandra dawson - Banging noise when closing off hot water taps
I have just had a combi boiler fitted, didn't gave a combi boiler before this.
Now I have problem with banging popes when closing off hot tops and after cistern has filled up.
Plumber wants to fit an arrester near stop.cock cost is about £200. Is this the best thing to cure the problem.
On 2017-12-14 by (mod) -
Indeed an arrester can stop banging pipes, though that cost *might* be a bit steep.
A Sioux Chief water arrester sold in the UK by Wickes is under £20 - but perhaps your plumber feels you need a larger device or that access to piping is going to require some costly labour.
Plumber charges vary widely depending on where you live but typically a plumber charges around £75 per hour.
So the cost estimate of £200 might be based on the plumber's estimate of 2 hours labour and the remainder in parts.
OR the plumber may also have a fee for travel.
On 2017-12-12 by isabelle - Is it normal for there to be a water hammer noise for 15 minutes after turning water back on?
My husband shut off the valve to a toilet for a minor repair in the tank (something like a float) and when he turned the valve back on he heard water hammer and immediately shut the valve back off.
I have read it is normal for this noise for the first 15 minutes, but he says we need to call an expert because it will cause damage.
Oour home was built in 2004 but is a concrete slab, but should have the regulators in them. he knows 0% about plumbing, but i want to try to simply turn the valve back on to the toilet. what should we do? thanks!
On 2017-12-17 by (mod) - NO
Isabelle
No it's not normal to hear water hammer for 15 minutes after working on the toilet.
More likely the problem was the specific velocity with which water was entering the toilet. Try opening the valve all the way - if the noise starts in that position try closing the valve a bit - and so on.
On 2017-08-15 by Meandpat - Do we need a new well to fix water hammer banging hammering noise?
We hear a loud hammering noise after flushing toilet or using water inside house. Is this doing damage? Can it be fixed without getting a new well?
On 2017-08-15 by (mod) - NO
Water hammer can do damage, causing leaks, burst pipes, damaged valves, and more subtly but more dangerous, leaks at tempeature/pressure relief valves can ultimately clog such a valve thus giving up an important safety device that is there to prevent a BLEVE - explosion.
On 2016-06-19 by middleaustralia - Banging water hammer when water is turned both on and off - Australia
I've read some of the water hammer comments and the noise seems to arise when a tap is turned off.However the water noise in my apartment in a 3 level complex consists of a loud "bang" (water turned on?)and then the sound of water rushing for about 5 seconds and then a loud bang when it stops.
There's an interval of about 15 mins or more and it happens again.I thought it was the water gardening pipe that runs under my unit but apparently that pipe wasn't being used at the time in question (3 a.m). I'm aware water hammer is caused by, say, turning a tap off or a washing machine stopping water flow when its full (water stopped) but this noise (first bang) occurs at the start when the water is apparently turned on.
My Building Executive Committee said the noise could be caused by tenants turning on and off their "over pressured taps" or from a dishwasher or washing machine. I'm glad you said a sound recorder could easily record the noise because I'm going to get one and try to get to the bottom of this. Any comment? Thanks
On 2016-06-19 by (mod) -
It sounds like water hammer to me, and a committee blaming the victim not the cause; record the sounds; consider installing water hammer arrestors.
There are both water-hammer reducing devices that can be installed on the piping near the valve and slower-closing valves that can be swapped in if needed.
I agree it's important to fix this as water hammer can cause damage, leaks, even unsafe conditions (as it can damage a relief valve).
Please see the suggestions at WATER HAMMER NOISE DIAGNOSE & CURE
On 2016-03-24 by Will - Intermittent banging when hot water turns on
My water heater was got replaced 6 months ago. Since then whenever the hot water gets turned on, there is a intermittent bang sound occurs. It only happens when hot water turns on.
Just wondering if this is related to the pressure valve. Any idea?
Thanks.
On 2016-03-24 by Mod err ator (mod)
The pressure relief valve won't itself cause water hammer, but as I said earlier it could leak dye to water hammer.
Banging noises can come from there and might be heard after running hot water as the water heater turns on and a combination of heat and scale in the water heater cause it to make banging, popping sounds.
See WATER HEATER NOISE DIAGNOSIS, CURE
IF there are no banging noises at the water heater, then heck out the live link at
Continue reading at WATER HAMMER NOISE DIAGNOSE & CURE
For water hammer explanation and cures. You'll see its probably a water velocity issue, fixed by adding a water hammer prevention device or a slow closing water valve.
On 2018-03-17 by (mod) - noise occurs with the heat pump online and with it offline.
If the heat pump operation is not affecting the presence or absence of a noise, determined by shutting down the heat pump system and observing that the noise recurs, I'd look elsewhere for its source.
On 2018-03-29 by ChadF
The noise occurs with the heat pump online and with it offline. After the plumbers replaced the pump, which had a built in check valve, the noise still occurs, but changed to a more random pattern.
It now occurs intermittently, sometimes while the heat pump is running, sometimes after the shower runs, or after/while the washing machine fills. No rhyme or reason.
Could debris become clogged in the manabloc and cause something like this? Is it safe to blow air through the manabloc? Running out of options.
On 2018-03-17 by (mod) -
Recapping the key issue
when the pressure is almost to the right level, the pipes (plastic) begin to shake and produce loud sound. The sound last for 15 to 60 seconds, and seems to stop when the pressure tank reaches the shut off setting. Tank is set to 20/40 psi now, when sounds started it was 40/60 psi.
I might experiment by closing valves to the ground-sourced heat pump to confirm that the problem does not occur except when the heat pump is online.
When I have seen this shutoff chatter at a well pump it's often been traced to a chattering check valve or control valve that's operating just enough to destabilize the pressure control switch near the cutoff pressure.
On 2018-03-17 by ChadF
Any further thoughts on this? Still having the issue. Plumbers have now replaced the well pump, which didn't work. Lucky they said they wouldn't charge me if it didn't fix the issue. We are literally going crazy having to have plumber after plumber i here and never getting anywhere. Really need some help folks. Thanks.
The pump relay switch doesn't chatter at all either. Thanks for the help!
The pump is in the well. Plumbers have told me the pump is 1/2 HP and is likely barely large enough, should have been 3/4 HP.
As far as pump having trouble reaching cut-off pressure, the sound happened when the cut-off was set to 60 PSI and was identical when reduced to 40 PSI. The pump's amp draw was too high at the higher cut-off but was humming perfectly at the lower. I'm no expert, but it doesn't seem like its having trouble reaching the cut-off pressure.
On 2018-03-01 by (mod) - domestic well and a ground-water sourced heat pump seems to cause noises
Is the pump in the well?
Is the pump relay switch chattering?
Is the pump having trouble reaching the cut-off pressure?
We may want to pursue those questions and think further before just adding water hammer control devices.
On 2018-03-01 by ChadF
I have a domestic well and a ground-water sourced heat pump that operates off the same well. I have pressure tank with 15 gallon draw and 44 gallon capacity.
Only recently, when water has been running for several minutes and then stops (like when the heat pump has run a cycle and stops drawing water), the well pump fills the pressure tank, when the pressure is almost to the right level, the pipes (plastic) begin to shake and produce loud sound.
The sound last for 15 to 60 seconds, and seems to stop when the pressure tank reaches the shut off setting.
Tank is set to 20/40 psi now, when sounds started it was 40/60 psi. The adjustment didn't help. I've now had two plumbers here a total of six times over two days and they can't find the issue. All they have managed to do is mask the sounds with foam pipe insulators, foam under the pressure tank, etc. - not addressing the actual cause.
They told me pressure tank operates fine, well pump is operating great too. Thanks for any suggestions, we are not sleeping well for a couple weeks now and need a solution. Appreciate the help!
On 2017-06-30 by (mod) - true that repeated high surges of water pressure can weaken pipe over time?
Great question, Scott. My gut feel is no if you're talking about typical residential water piping materials and if we ignore the connections - it's a connection that is more likely to wiggle, weaken and come loose in response to water hammer.
There is some expert material failure research that digs more carefully into your question, as well as some theoretical modeling such as
- Schmitt, C., G. Pluvinage, E. HADJ‐TAIEB, and R. Akid. "Water pipeline failure due to water hammer effects." Fatigue & Fracture of Engineering Materials & Structures 29, no. 12 (2006): 1075-1082.
Abstract:
A numerical model has been established in order to simulate the propagation of pressure waves in water networks. The present model formulation is based on a system of partial hyperbolic differential equations. This system has been solved via the characteristics method.
The current model provides the necessary data and the necessary damping of water hammer waves, taking into account the structure of the pipe network and the pressure loss. The numerical algorithm estimates the maximum pressure values resulting from the water hammer when closing valves in the network and consequently, the maximum stresses in the pipes have been calculated.
In the case of simultaneous closing of several valves, the over pressure can exceed the admissible pressure. In this case, the severity of a defect such as a corrosion crater (pit) has been estimated by computing a safety factor for the stress distribution at the defect tip. This allows the applied notch stress intensity factor to be obtained. To investigate the defect geometry effects, semi-spherical and semi-elliptical defects are deemed to exist in up to one-half of the thickness of the pipe wall.
The outcomes have been introduced into the structural integrity assessment procedure (SINTAP) failure diagram assessment (FAD) in order to obtain the safety factor value. Conventionally, it is considered that a failure hazard exists if this safety factor is less than two. - Halliwell, A. R. "Velocity of a water-hammer wave in an elastic pipe." Journal of the Hydraulics Division, 1963, Vol. 89, Issue 4, Pg. 1-21
Abstract:
The general expression for the velocity of a water-hammer wave through a fluid in an elastic pipeline is evaluated. This result is applied to the following common practical cases: A rigid pipeline; thick-walled and thin-walled elastic pipelines with various longitudinal constraints; rock tunnels; and tunnels having a steel, or concrete, or steel and concrete lining.
The results obtained are compared with those given in several standard reference books. It is shown that certain errors do exist, and considerable confusion does arise with these texts due to the fact that the assumptions made by the authors have not been clearly stated.
Most of the confusion and errors in the texts are concerned with the effect of the external constraints or of Poisson's ratio, and the error involved is, in general, small (less than 10%). Nevertheless, this error may be important, and textbooks should make quite clear any assumptions made in deriving their results. - Lahlou, Zacharia Michael. "Water hammer." Water Encyclopedia (2001).
Reviewing those and other sources suggest that some pipes could fail along the pipe length from water hammer.
Water hammer is not going to happen in drain pipes carrying wastewater - as expressed in your question - but rather in supply pipes that are under pressure.
On 2017-06-30 1 by Scott
Is it true that repeated high surges of water pressure can weaken pipe over time? If so, would this mean one could extend the life of discharge plumbing pipes by moderating the flow of wastewaater?
On 2017-04-03 by (mod) - Do hammer suppressors go bad OR do they get clogged up and stop working
A water hammer arrestor can be damaged by mis-handling during installation, as Watts points out in their installation guide.
But typical water hammer arrestor design includes a sealed chamber that should not clog nor fail by leakage.
If the water hammer arrestor never worked satisfactorily I suspect that it was installed in the wrong location or that the wrong size was selected.
Water hammer an occur on a plumbing system as a "new" issue also if / when any valve is changed to a different type, such as a fast-closing zone valve on a heating boiler.
On 2017-04-03 by R.S.
AUTHOR:R.S. (no email)
Do hammer suppressors go bad OR do they get clogged up and stop working because of that?
On 2017-03-20 by (mod) re: hot water pressure loss and banging pipes
Searching InspectApedia using the search box just above and looking for "HOT WATER PRESSURE LOSS" finds this article that may help you diagnose the trouble you describe:
inspectapedia.com/plumbing/Hot_Water_Lost.php
I think I'd start by looking for scale in the water heater or calorifier or geyser or hot water cylinder - depending on where you live.
On 2017-03-20 by Luis G.
I have pipe banging I lose pressure on the hot water I still have pressure in the cold water what can cause this
On 2017-02-17 by Mary
How do I fix the hammering on my water heater
On 2016-10-25 by (mod) re: night time knocknig noises
Bill, if you're sure this is a piping noise, yes the watering system could be the cause. See if the watering timer setting corresponds with the noise.
On 2016-10-16 by BIll
LOud knocks between 2am and 4|30am. NO inside or outside water is running at that time. Our home is on a water supply with 300 other homes. The water supply company has 3 wells in our community. DUring the day there is no knocking, thumping, sputtering of any kind. THe noise is on the side of the house with the meter.
Is pressure from water supply causing this when someone's irrigation, or swimming pool turns on, or flush of toilet from neighbor between the hours of 2am and 4:30am?
On 2016-10-25 by (mod) Banging Pipes in Ontario
David,
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On 2016-10-04 by David H. - a loud banging sound from the plumbing when they use the Guest washroom
We have a guest bathroom which is not all that frequently used. Recently friends from Poughkeepsie New York visited us here in Ontario. I was surprised to hear a loud banging sound from the plumbing when they use the Guest washroom.
This morning after their departure I reviewed this very helpful page and learned about the causes of this irritating hammer-like sound. Happily the solution was easy and one I learned about from this page. I adjusted the water flow by opening the water shut off to the side of the sink on the hot water side and the noise went away. Thank you very much! The next time my friends from Poughkeepsie visit I won't have to be embarrassed by my plumbing sounds. :-)
On 2016-05-24 by Rose - water heater makes a hammering noise
My hot water heater makes a hammering noise when I've done a few loads of laundry. What can the cause of this be? I still get hot water but the noise worries me.
...
...
Continue reading at WATER HAMMER NOISE DIAGNOSE & CURE or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.
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Citations & References
In addition to any citations in the article above, a full list is available on request.
- ANSI Standard S12.60 – 2002, “Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools.”
- ASHRAE, . 2007 ASHRAE Handbook – HVAC Applications, p. 47.34, Table 44, Plumbing Noise Levels
- ASPE, "Acoustics in Plumbing Systems", [PDF] merican Society of Plumbing Engineers, Continuing Education, (October 2012), retrieved 11/2/2015, original source: https://www.aspe.org/sites/default/files/webfm/ContinuingEd/PSD_CEU_192Oct12.pdf
- Blacoh™ Fluid Control, Website: http://www.blacoh.com, Tel: 951-239-3930, BLACOH Fluid Control, Inc. 601 Columbia Ave, Bldg D Riverside, CA 92507 USA Phone: 888.494.3179 951.239.3930 Fax: 951.342.3101 Email: sales@blacoh.com Blacoh sells Sentry pulsation dampeners and surge suppressors/LI>
- Douststop Anti Hammer Water Control Valve, Doust, Australia, also available online from http://www.bunnings.com.au/
- Duan, Huan-Feng. "Discussion of “Analysis of PVC Pipe-Wall Viscoelasticity during Water Hammer” by AK Soares, DIC Covas, and LFR Reis." Journal of Hydraulic Engineering 136, no. 8 (2010): 547-548.
- Brian Boman, "Chapter 21, Hydraulics", University of Florida, Indian River Research & Eductation Facility, 2199 South Rock Road, Fort Pierce, Florida 34945-3138 Tel: (772) 468-3922, Email: bjbo@ufl.edu, retrieved 3/3/2014, original source: http://irrec.ifas.ufl.edu/citrusbmp/ Water%20and%20FL%20Citrus/21%20Chap21.pdf
- J.R. Smith Manufacturing, 2781 Gunter Park Dr. E. Montgomery, AL 36109-1405, USA, Tel: (800) 467-6484, Email: info@jrsmith.com, Website: http://www.jrsmith.com/
- Kwolkoski, Jeffrey P., P.E., "An effective new approach to isolate plumbing stub-outs in residential construction", [PDF] Inter-Noise 2006, December 2006, retrieved 11/2/2015, original source: http://waveengineering.co/wp-content/uploads/2012/06/Effective-new-approach-isolate-plumbing-stub-outs-in-residential_in06_755.pdf
- Oatey Plumbing, website: http://www.oatey.com/ Oatey U.S., 4700 W.160th Street Cleveland, Ohio 44135, PH: (800) 321-9532, and Oatey Canada: 218 Wilkinson Road Unit 3, Brampton, Ontario Canada L6P 4M4, PH: (800) 321-9532 email: customerservice@oateyscs.com
- Oatey Plumbing, Website: http://www.oatey.com/ Oatey U.S., 4700 W.160th Street Cleveland, Ohio 44135, USA, PH: (800) 321-9532, and Oatey Canada: 218 Wilkinson Road Unit 3, Brampton, Ontario Canada L6P 4M4, PH: (800) 321-9532 email: customerservice@oateyscs.com
- Reece Plumbing Centres, "Understanding Water Hammer", Reece Plumbing Centres, Email: outlet@reece.com.au Website: reece.com.au, Outlet (Customer Update Publication), August 2004, retrieved 11/2/2015, original source http://www.reece.com.au/assets/Uploads/2004Aug.pdf
- Silverstorm Water Hammer Arrestor, Australia, also available online from http://www.bunnings.com.au/
- Sioux Chief Water Hammer Arresters, Website: http://www.siouxchief.com,Sioux Chief, 24110 South Peculiar Drive Peculiar, MO 64078 USA, Phone 816-779-6104 800-821-3944, sold in Australia via https://www.masters.com.au Example: Sioux Chief 660-HB 3/4" water hammer hose arrestor, or Sioux Chief 660-TCO 1/4" water hammer arrestor tee for ice makers
- Watts, 815 Chestnut Street, North Andover, MA, USA 01845-6098, web search 09/18/2010 original source: http://www.watts.com/pages/learnAbout/reducingValves.asp?catId=64
- Watts Water Hammer Arrestors (Watt Series 05) or Watts Water Pressure Regulator (Watts Series 1156 or 25AUB) can correct water hammer water hammer-related leaks such as may occur at
a BACKFLOW PREVENTER valve or temperture/pressure relief valve
Watts Water Products, 815 Chestnut Street, North Andover, MA, USA 01845-6098 - Wetherill, Ewart A., "What dreadful noise of water in mine ears!* - Plumbing Noise - a Phenomenon of Urban Living", Sound and VIbration, June 2008, p. 12-16, Ewart A. Wetherill, Alameda CA, Website: www.SandV.com, Author's email: redwetherill@sbcglobal.net
- In addition to citations & references found in this article, see the research citations given at the end of the related articles found at our suggested
CONTINUE READING or RECOMMENDED ARTICLES.
- Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. Tel: (416) 964-9415 1-800-268-7070 Email: info@carsondunlop.com. Alan Carson is a past president of ASHI, the American Society of Home Inspectors.
Thanks to Alan Carson and Bob Dunlop, for permission for InspectAPedia to use text excerpts from The HOME REFERENCE BOOK - the Encyclopedia of Homes and to use illustrations from The ILLUSTRATED HOME .
Carson Dunlop Associates provides extensive home inspection education and report writing material. In gratitude we provide links to tsome Carson Dunlop Associates products and services.
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