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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Plumbing Questions >> water hammer https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1160299648 Message started by mercedesjb on Oct 8^th, 2006, 10:27am

Title: water hammer
Post by mercedesjb on Oct 8^th, 2006, 10:27am

i get water hammer really badly only when i turn on the cold tap in the downstairs bathroom.
is there a technique for getting rid of the trapped air - by bleeding etc?

Title: Re: water hammer
Post by big_all on Oct 8^th, 2006, 1:38pm

heeelllooo mercedesjb :D:D:D

waterhamers can also be caused by ball valves pulsing[dont know the proper term ::)]

basicly what happens

you turn on the tap the float rises slightly causes a ripple you then shut the tap off the pressure then pushes the float down causing a second wave this causes the float to oscilate causing more waves ect

a solution is find the offending float and if its metal bend it slightly off centre to slightly increase the friction

you can also try things like slightly adjusting the water level screw on the float adding a few ounces to the float arm
basicly anything that breaks the rythm ;D

Title: Re: water hammer
Post by thescruff on Oct 8^th, 2006, 9:34pm

Think you will find he means a quarter turn basin tap thats connected to the mains.

Try reducing the flow at the stopcock slightly and clip any pipes that not, especially plastic ones.

Title: Re: water hammer
Post by sparky415 on Oct 9^th, 2006, 6:46pm

While on the subject of 'water hammer' please help me with this one

My mums bungerlow has one stopcock outside that feeds the bathroom, kitchen
and seperate toilet with a basin,(no internal stopcock)

Since having the kitchen taps replaced with ceramic leaver taps,
she has been experiencing 'water hammer' when any of the taps are turned on or the toilets
flushed

I have tried juggling with the stopcock and the 'ballafix' valves
What shall I try next please?

Sparky415

Title: Re: water hammer
Post by thescruff on Oct 9^th, 2006, 7:49pm

Lever taps will always be more prone than normal taps because they shut off quick, which in turn shocks the water. if you tried turning them off slowly they should be ok.

Any unclipped pipes will make the situation worse, the task is to find them. behind the units is a good place to start, followed by any risers to above (ducts).

Title: Re: water hammer
Post by sparky415 on Oct 9^th, 2006, 9:29pm

Scruff,

It is doing it with all three cold taps, also if more than one tap is used at a time (only the kitchen taps have been changed for levers)

I haven’t checked for unclipped pipes but they have lived there for years and its not happened before and I don’t think anything else has been changed

Sparky415

Title: Re: water hammer
Post by thescruff on Oct 9^th, 2006, 10:23pm

Does it do it all the time or just when you turn the taps off quick.

I would still look under and around the sink unit for plastic pipes just slung in by your average kitchen fitter.

Is the banging just a single bang when you shut the taps down or a continous bang all the time your using the tap.

Title: Re: water hammer
Post by sparky415 on Oct 9^th, 2006, 10:54pm

Mercedes,
Sorry to hijack your thread

Scruff,
It does it all the time the taps are running,
The pipes are all copper with Yorkshire fittings mostly through walls or up from the solid floor
A continuous banging/humming/buzzing noise

Title: Re: water hammer
Post by thescruff on Oct 9^th, 2006, 11:12pm

Ok so something has come loose, most likely the jumper in the stopcock.

Silly question has she got a water meter.

Title: Re: water hammer
Post by sparky415 on Oct 10^th, 2006, 6:43am

The stopcock was new last year

I will ask her tonight but I don’t thinks shes on a water meter

The jumper? Can I get her to knit a new one?

Title: Re: water hammer
Post by sparky415 on Oct 15^th, 2006, 9:32pm

Scruff
No She doesn’t have a water meter
What’s a Jumper?

Sparky415

Title: Re: water hammer
Post by thescruff on Oct 16^th, 2006, 10:47pm

The jumper is the brass bit that holds the washer.

Some stopcocks the jumper is fixed and some are loose (older type) if you take the valve to bits andthe brass bit fall out, then tap the end of the spindle with a hammer so its a tight fit

Title: Re: water hammer
Post by sparky415 on Oct 16^th, 2006, 10:58pm

Scruff,

The stopcock is outside, It was replaced by the water board last year
Its one with a blue plastic tap/handle on top (its about 18” underground in a narrow hole)
Is it fixable without digging up do you think?
Do you often pass Oxford with your hammer? ;)

Sparky415

Title: Re: water hammer
Post by thescruff on Oct 16^th, 2006, 11:06pm

If its a blue plastic one then that isn't the problem

Back to the lever taps or unclipped pipes ::)

Title: Re: water hammer
Post by sparky415 on Oct 16^th, 2006, 11:16pm

Thanks Scruff

S

Title: Re: water hammer
Post by sparky415 on Oct 20^th, 2006, 6:43pm

Scruff,

She had the plumber that fitted the leaver taps come back
He fixed it by changing the washer in the tap :-[

It confused me as all the cold taps made the noise appear
(and I thought electric was confusing sometimes)

Thanks for your help :)

Sparky415

Title: Re: water hammer
Post by thescruff on Oct 21^st, 2006, 11:10am

Its usually something simple, but good to know they got it sorted.