Help, my bathroom tap is a machine gun!

Forums › Home Workshop DIY › Help, my bathroom tap is a machine gun!

mbearsley

15 posts

Geek

#95813 13-Jan-2012 20:34

If I dare to turn on the cold tap over the bathroom basin it will go fine slowly. But if I turn it on a bit further to the normal hand washing flow it suddenly rattles and vibrates at an unbelievable volume. The noise would be easily heard way down the street. The tap actually vibrates violently. The noise and vibration starts at full volume and frightens the hell out of the user. I inspected the tap washer and though it looked ok, I turned it over anyway, but it made no difference at all. Anyone experienced this sort of violence from their taps?

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152 posts

Master Geek

#568610 13-Jan-2012 20:40

Sounds like 'water hammer' http://en.wikipedia.org/wiki/Water_hammer

Maybe one of the guys can help you, Im not too good on things like that. :)

keewee01

1737 posts

Uber Geek

Trusted

#568615 13-Jan-2012 20:53

Our old plumbing was doing that. Would make one hell of a racket!!!

Interestingly, while they were upgrading the water supply in our street the sound disappeared and hasn't been back since - after being there every day for well over a year.

scuwp

3886 posts

Uber Geek

#568621 13-Jan-2012 21:15

I take it it's an old fashioned standard tap with a rubber washer?

If it hasn't done it before then it's the tap at fault.

Change the washer and the small plunger that the washer fits onto (if its separate). When they wear out the water pressure spins the plunger around and it bangs back and forth. Can cause damage elsewhere in your house plumbing so best you don't let the noise continue and get it seen to.

If that doesn't work you are probably in for a new tap.

Lazy is such an ugly word, I prefer to call it selective participation

keewee01

1737 posts

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#568623 13-Jan-2012 21:24

scuwp: I take it it's an old fashioned standard tap with a rubber washer?

If it hasn't done it before then it's the tap at fault.

Change the washer and the small plunger that the washer fits onto (if its separate). When they wear out the water pressure spins the plunger around and it bangs back and forth. Can cause damage elsewhere in your house plumbing so best you don't let the noise continue and get it seen to.

If that doesn't work you are probably in for a new tap.

Well - that is what our plumber told us too! He said the taps were old enough that the plunger bit had worn and we'd not be able to replace them so were up for new taps and associated plumbing. And I quite believe that is the truth.

But, interestingly, since the changed piping in the street our issue has disappear. Very, very strange.

mbearsley

15 posts

Geek

#568631 13-Jan-2012 21:40

Thanks guys. I did check that the spindle that the washer is on was not worn sloppy and everything looked good. I might have to have another look at it. Thanks again.

gzt

17159 posts

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Lifetime subscriber

#568698 14-Jan-2012 09:25

If you have two taps the same you could swap the mechanism from one tap to the other and see if there is any difference.

mbearsley

15 posts

Geek

#568733 14-Jan-2012 11:04

Now that is a clever idea but the only tap that is the same is the hot tap beside it. I suppose I could swap those and if the washers are different as they should be, swap the washers over. Thanks, I'll do that as soon as I get a chance.

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richms

28192 posts

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#568763 14-Jan-2012 13:00

As its old enough to have 2 taps it is quite likly your hot is on low pressure so it will not happen with the washer etc from the cold when swapped.

In some taps it is ment to float around as a crude form of backflow prevension so just because it may have movement doesnt mean that There is a problem. I ended up swapping my outdoor tap for a washing machine one since all the $7 ones vibrated with the irrigation system running off it

Richard rich.ms

JimmyLizar

321 posts

Ultimate Geek

#568771 14-Jan-2012 13:36

Technically, what you describe is not 'water hammer'. Water hammer is that bang or clattering you get when you shut the tap off too quickly.

This sounds more like the cold water pipe (probably copper) is vibrating at its resonant frequency as the water is forced through it.

A possible soultion is to secure the pipe to the supports (eg. floor joist, bearer etc) in a few more places using the appropriate clips. This may stop the pipe vibrating enough so it wont reach its resonant freqrency.

However, in saying that, I would suggest talking to a friendly plumber. They are bound to know more about it than anyone on a electronic technology forum.

.....c'mon sucker lick my battery........
binary solo...0000110000110000111...

mbearsley

15 posts

Geek

#568774 14-Jan-2012 13:47

Yes I have done a lot of Googling and I agree it is not water hammer. as far as it doesn't happen when I turn the tap off, it happens when the tap is turned on enough to wash your hands quickly. It is the violence of the vibration and the volume of the high speed hammering sound that is frightening. I can tell it will damage something so we don't use the cold tap Here is the big problem - The house is so low to the ground, like a one foot gap that it is impossible go get under there. Couldn't get it insulated either. I hope I never get a leak under there!!!

keewee01

1737 posts

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Trusted

#568776 14-Jan-2012 13:50

JimmyLizar: Technically, what you describe is not 'water hammer'. Water hammer is that bang or clattering you get when you shut the tap off too quickly.

This sounds more like the cold water pipe (probably copper) is vibrating at its resonant frequency as the water is forced through it.

A possible soultion is to secure the pipe to the supports (eg. floor joist, bearer etc) in a few more places using the appropriate clips. This may stop the pipe vibrating enough so it wont reach its resonant freqrency.

However, in saying that, I would suggest talking to a friendly plumber. They are bound to know more about it than anyone on a electronic technology forum.

Actually - that sounds more reasonable in my situation as when they upgraded the water supply and install the water meter the problem went away.

gzt

17159 posts

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Lifetime subscriber

#568781 14-Jan-2012 14:06

mbearsley: Here is the big problem - The house is so low to the ground, like a one foot gap that it is impossible go get under there. Couldn't get it insulated either. I hope I never get a leak under there!!!

I have a friend who is an apprentice electrician. Believe me, it is possible, you just need an apprentice. : ).

The insulators probably did not want the job, but who would.

That said, it is dangerous. An electrician died last year in that situation.

JimmyLizar

321 posts

Ultimate Geek

#568783 14-Jan-2012 14:12

keewee01: Actually - that sounds more reasonable in my situation as when they upgraded the water supply and install the water meter the problem went away.

There is probably a myriad of reasons why it fixed the problem. Changing the length of pipe, changing the pipe materials, changing flow rate (pressure) all could have contributed to your solution.

mbearsley: Phone a plumber. They might be able to dampen the vibration somewhere or install an adjustable water pressure reducing valve that might solve your issue. It could be that a minor change in any number of variables (as per keewee01's situation above) could solve your issue.

.....c'mon sucker lick my battery........
binary solo...0000110000110000111...

mbearsley

15 posts

Geek

#568792 14-Jan-2012 14:29

You're just trying to cheer me up :-) No really, if an apprentice could get under there he would be too thin and weak to do anything. I have been playing around with puting some high density foam between the pipe to the tap where it goes through two holes in the cabinette it is attached to and the sides of the hole so it doesn't touch the wood. The hammering doesnt always happen now but the tap squeels as the water runs through it. If it ever stops raining I will turn the water off and have another look at the spindle and washer. Something is not right in there me thinks.

mbearsley

15 posts

Geek

#568794 14-Jan-2012 14:37

Jimmy Lizar - If you look at my avatar you will see I am a grey haired old pensioner. There is no way I could afford to pay a plumber to drive out to where I live and certainly not to pay for a pressure reducing valve, even though I think you are right. Reducing the pressure would certainly help. I can tell by the squeal that the water is going through at an incredible rate.

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