Water hammer - Solutions ??

Discussion in 'Plumbers' Talk' started by tph1, Feb 8, 2005.

  1. tph1

    tph1 New Member

    After employing the services of a family friend to do the 1st fix pipework, I am now paying the price.

    A professional plumber has just finished my bathroom and we have found serious water hammer when the taps are turned off suddenly (or the WC cistern finishes filling). We suspect the cause is a combination of not securing the pipes properly and the use and position of too many tee connections. Unfortunatly the pipes are now under 2 sheets of timber, as well as the new bathroom suite. Ripping the floor up is NOT an option.

    Aside from the noise I understand that water hammer can sometimes loosten joints over time. Is this a common occurance ??

    As a remedy i have seen shock arrestors on the net (one made by micron keeps popping up). Can i fit one (or more) of these onto any length of easily accesible pipe (ie under the bath taps) and still expect good results, or does it have to go in a particular place ??

    After searching on this forum many plumbers recommend the homemade solution of a length of pipe with an air lock and a stop end to "cushion" the shock, however my plumber tells me this is against regulations as you are creating a dead leg in the water system in which bacteria could breed.

    Can anyone suggest my next steps without reminding me I should have employed a professional plumber in the first instance (who all actually quoted me virtually the same as my final cost anyway, DOH!)

    Many thanks
     
  2. andyboy

    andyboy New Member

    Have you tried fluidmaster valves for toilet cisterns and water tanks, they fill from the bottom so avoid ripples in the water which makes the float bounce.
     
  3. Stuart

    Stuart Guest

    I had water hammer with my washer/dryer and sorted it by fitting a 'Micron' shock arrestor. It cost me £19 and did the job. It has to be fitted as close a possible to the valve causing the problem. For my wahsing machine I fitted to where the flexible hose connects to the copper pipes. The flexible hose still shakes as the valve opens and closes but there is no hammer in the copper pipes and hence no noises around the house.
    I had so much trouble getting anyone to tell me if it would work that I just had a go and it did.
    You could fit a small pipe to trap air but at £19 for the proper item I wouldn't bother and the proper item is maintenance free - eg you won't have to worry about the air trap pipe filling with water.
     
  4. tomplum

    tomplum Active Member

    hi tph
    i don't think the number of and position of tee's will cause water hammer, from what you describe it is not water hammer, but sudden water stop, this could be because the restictor has not been used on the toilet ballvalve, or a mixertap / showermixer is not up to standerds. or simply the stopcock is not fully open. check these first, is it a combi ? most combis will cause water noise if you turn the hot tap on and off in quick succsetion, i think it unlikely to be the first fix.
    that my 2 cents worth, hope it helps
    tom
     
  5. r2d2

    r2d2 New Member

    Water hammer usually occurs when high-pressure flow of water is suddenly arrested as in a tap being turned off quickly and will momentarily subject the whole system to a pressure almost double that of the incoming water and yes it could cause a pipe to develop a leak. What is your incoming mains pressure?. Is their a pressure reducing valve fitted?. Have you tried reducing the flow rate at the tap using the isolating ballvalve or you could reduce the flowrate at the mains stopvalve. Regards r2d2.
     
  6. tph1

    tph1 New Member

    Hi

    sounds like this is exactly what i need.

    Not sure what you mean when you say it has to be fitted as close as possible to the valve causing the problem, as every tap / valve in the bathroom currently causes the problem - if it is turned off suddenly.

    In the first instance i will fit one to the cold tap pipework feeding the bath (because it is easily accessible).

    Cheers
     
  7. tph1

    tph1 New Member

    hi tph
    i don't think the number of and position of
    tion of tee's will cause water hammer, from what you
    describe it is not water hammer, but sudden water
    stop, this could be because the restictor has not
    been used on the toilet ballvalve, or a mixertap /
    showermixer is not up to standerds. or simply the
    stopcock is not fully open. check these first, is it
    a combi ? most combis will cause water noise if you
    turn the hot tap on and off in quick succsetion, i
    think it unlikely to be the first fix.
    that my 2 cents worth, hope it helps
    tom


    Are you the guy who did my pipework in the first place ???? ;)

    Sudden water stop IS water hammer isn't it ? If it isn't then nearly every website I've been on yesterday is wrong

    http://www.irrigationtutorials.com/waterhammer.htm

    Mixer shower is an expensive Triton

    Stop tap is not fully open. I closed it several turns to reduce the pressure... and therefore the water hammer effect. I understand this cannot be a permanent solution, and a pressure restrictor is preferred in the long term. When the stop tap was fully open, the noise was vastly increased.

    It is a combi boiler, although the noise is not restricted to the hot pipes... in fact it is actually slightly worse in the cold (presumably because they are feeding directly from mains and therefore the pressure is slightly higher)

    I do have to laugh cos thats exactly the diagnosis I would expect from my first fix plumber... everything else is at fault but his work !

    Many thanks for taking the time to answer anyway
     
  8. tomplum

    tomplum Active Member

    tph1
    i can see now why your family friend did not come back to finish your job, your the sort of person who sits on his shoulder and says (in a harry enfield way ) you don't want to do that, you should do this, you are reading american tutouials designed to make money, if they know how to cure water hammer, why are you asking again ? look where the waters mix, cost of items won;t prevent water hammer if the situation is wrong.
    i try to help but if you won't listen put up with it..
     
  9. tph1

    tph1 New Member

    tomplum, I use this forum because 98% of the people on it are intelligent, knowledgeable & helpful building professionals. I have only had two answers from you and with the greatest respect both are gibberish.

    The "american tutouial" that you refer to, if you have even taken the time to read it (which I doubt), is a very detailed insight into the problem (even if it is written in annoying American dialect). How, when it is obviously FREE to read, is it "designed to make money"???

    As for "why am I asking again", why does anyone ask a question on these forums ???? In life, if you have a problem that you do not know much about, it is always a good idea to seek as much advice as possible, from as many varied sources as possible. Then, if you are a reasonably intelligent person you can make an informed judgement on the situation.

    Let's suppose I had NOT had any other answers but your original one, and I did not have the benefit of having a plumber with 25 years experience IN MY HOUSE RIGHT NOW, and I had no access to any further information. Right now I would be buying and fitting a restrictor on the WC, replacing my £200+ mixer shower, opening up the stopcock (even though partially closing it actually helped the problem), and calling a heating engineer out to look at my brand new boiler. How will any of these expensive measures solve the water hammer I get from turning the cold tap off at the basin or bath ???

    "look where the waters mix"... i mean what the hell does that mean ??? It sounds like a cryptic clue from a Lord of The Rings script - aside from the fact I don't have any mixer taps - if you mean my shower, then once again, the problem is not related to the shower ! READ MY ORIGINAL QUESTION ! I do not mention the shower once ! You brought the shower up !!

    Whilst we are on the subject of Harry Enfield, I can only feel sorry for any of your customers who fall for your mis-diagnosis, only to end up paying you "LOADS-A-MONEY".

    In the mean time, here's some MORE FREE information on water hammer:

    http://home.howstuffworks.com/framed.htm?parent=question89.htm&url=http://www.buildingadream.com/techbriefs/waterhammer.htm

    http://home.howstuffworks.com/question89.htm

    http://www.extra.rdg.ac.uk/wkc1/DIY/plumbing/msg00149.html

    Now that you've got me suitably wound up, I really must CALM DOWN, CALM DOWN.
     
  10. tomplum

    tomplum Active Member

    now then young man, didn't your parents learn you any manners ? you seem good at writing and reading i'll give you that, but dear me what a nasty tongue you have sir.i note that your posts are made in the morning, so you are using your employers time and equipment, whereas i post at night after i have earned my crust, honestly, and soiled my hands and cloths working for people who trust me and are glad of my work and advise,many come back time and again to pay me loads of money cos they like me.i hope that the 98 persent of inteligent people on this site see you for what you are, a arrigant self opinionated ,diy no hoper, who cheats his boss and drives a desk, i bet you also have a woman for a supervisor.
    my advise today... get a life.
     
  11. tph1

    tph1 New Member

    I despair sometimes...
     
  12. jinxie

    jinxie New Member

    Wow. I enjoy reading forums, even when folk get a bit snarly. There is a lot of good information that good people are willing to share with everyone.

    I generally ignore when people make rude assumptions about others (morning posts mean you MUST be on the clock... because no one in UK works nights??), but I have to admit I was rather shocked that anyone would use the line 'i bet you also have a woman for a supervisor' as an insult. Hopefully someone grew up since these posts!
     
    Sean_ork likes this.
  13. BuilderMCR

    BuilderMCR Active Member

    TPH1 I think you should do a search on YouTube for tomplum. You could probably learn a fair bit from him.

    And trying what he's told you may save you some money.
     
  14. Sean_ork

    Sean_ork Screwfix Select

    same tune different decade
     
  15. tom.plum

    tom.plum Screwfix Select

    why would anyone want to drag up a 2005 thread ? anyway wonder if TPH ever got it sorted he seemed a nice bloke really just a bit hard of thinking, perhaps he'll post the outcome, I'm sure he's found by now that the appliances he has dictates the amount of tee's and plumbers don't just guess how many to put in, ah well, I'm glad people find these threads entertaining,:)
     
  16. Ray Retired

    Ray Retired Active Member

    "look where the waters mix"... i mean what the hell does that mean ??? It sounds like a cryptic clue from a Lord of The Rings script..."

    Hehehe... Best laugh I've had since me tea! :)

    On a serious note tho regarding this bit... "the homemade solution of a length of pipe with an air lock and a stop end to "cushion" the shock, however my plumber tells me this is against regulations as you are creating a dead leg in the water system in which bacteria could breed."

    Any truth in that?

    Asking due to the firm that installed me present day combi-boiler capped off the pipe that fed the tank in the attic, but left it connected to the run that feeds the bathroom. Did they create a "dead leg" and if so, should I be calling 'em to come make it good?
     
  17. tom.plum

    tom.plum Screwfix Select

    Yes Ray thats a fact, dead legs are against regulations, but if that pipe is feeding the bathroom its not a dead leg,
     
  18. Ray Retired

    Ray Retired Active Member

    Ta for that Tom.

    I didn't explain the pipe run so well... And not sure it makes any difference, but for peace 'o mind bout bacteria when the grandkids stay over.

    The pipe in question feeds the bath, sink and toilet (in that order) then continues on and up into the attic where it got capped off. My thinking is that the vertical section of pipe after the toilet will be air-locked, is that a different kettle of fish from creating a 'dead leg' say between the bath and sink?
     
  19. tom.plum

    tom.plum Screwfix Select

    the dead leg in your case Ray is the section after the toilet up to the cap in the attic, a good section will be airlocked but water will compress a section of the air with water thats not moving, this is where the bacteria breeds,
     
  20. Ray Retired

    Ray Retired Active Member

    Cheers again Tom :)

    I'll be having 'em back out to explain why the pipe run wasn't terminated using an elbow to supply the toilet and also if removal of the redundant pipework was gonna be a pita why wasn't it at least disconnected.

    I should add you plumber types never fail to leave me scratchin' me head. I offered the young lad serving his time the redundant hot water cylinder & the rest of the pipework they'd ripped out for weigh in, only to be knocked back with a 'thanks, but nah.'... Fair enuf t'was only 80 odd quids worth, but for a half hour drive to the scrapyard I'd 'ave thawt it decent back pocket spends for a young 'un. I guess times have changed huh?
     

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