[ichikiriyama]

Here's the issue.

Whenever my cold tap is turned off quickly, the pipes in the house vibrate wildly. It a loud, dull noise. Build up pressure I assume.

It happens in every room but only the cold tap, not the hot. If it were just that, I could live with it - I'd just turn the tap off slowly, bit it also does it when the washing machine fills up. When it's finished filling up and the water intake switches off, the god awful noise starts.

The only way to fix it is to turn the cold tap on full blast and then turn it off slowly.

Any plumbers on here that can assist?

[paulktreg]

Try turning the tap down a little on the cold water supply to the house?

[Phil57]

By no stretch of the imagination am I a plumber..........................
Your system has an air lock, try opening all of the cold taps and flush all the loo's, then shut them all off before the loo cistern has finished refilling.
Hope this helps.

[neilios]

Probably need to fit a pressure reducing valve on the incoming mains just after the stop tap...
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[ichikiriyama]

Thanks for all the replies. Ilk have a proper chance this weekend to play around with it.

It's funny because I've been in this house for about 5 years and it's only started doing it over the last 3 months.

I can't think of anything that has changed to make it start now.

[neilios]

Originally Posted by ichikiriyama

Thanks for all the replies. Ilk have a proper chance this weekend to play around with it.

It's funny because I've been in this house for about 5 years and it's only started doing it over the last 3 months.

I can't think of anything that has changed to make it start now.

The dynamic pressure from the incoming mains might have changed,there's no way a householder would know,or it could be a faulty tap,shower valve or even a toilet inlet valve causing the water hammer..

[961]

The incoming cold water pressure from the mains supply may have increased. When you turn a cold tap off you get the noise you describe

Your problem is water hammer, and may be caused by an increase in the mains water pressure after, for example, the mains pipes have been renewed or scoured. If you go to the stop cock at the pipe where your mains water enters the house and turn the tap to reduce the mains pressure as it enters the house you will reach a point at which the incoming water pressure is high enough to supply water at a satisfactory pressure for all your appliances, dishwashers, washing machines and cold water tank (if you have one) but low enough to prevent the symptom you describe

Here's a description of the problem

grrrr.. still can't fix my houses water hammer, so what next - DIYnot.com - DIY and Home Improvement

It's possible a pipe within the house has become loose, but I'd try reducing the incoming pressure first as this may well cure your problem

[ichikiriyama]

All these replies are great and hopefully come the weekend I'll have it sorted.

Thanks again.

[neilios]

Originally Posted by 961

The incoming cold water pressure from the mains supply may have increased. When you turn a cold tap off you get the noise you describe

Your problem is water hammer, and may be caused by an increase in the mains water pressure after, for example, the mains pipes have been renewed or scoured. If you go to the stop cock at the pipe where your mains water enters the house and turn the tap to reduce the mains pressure as it enters the house you will reach a point at which the incoming water pressure is high enough to supply water at a satisfactory pressure for all your appliances, dishwashers, washing machines and cold water tank (if you have one) but low enough to prevent the symptom you describe

Here's a description of the problem

grrrr.. still can't fix my houses water hammer, so what next - DIYnot.com - DIY and Home Improvement

It's possible a pipe within the house has become loose, but I'd try reducing the incoming pressure first as this may well cure your problem

Turning the stop tap down wont stop it..

[961]

Originally Posted by neilios

Turning the stop tap down wont stop it..

Did with us because of excessive mains pressure

I agree it won't cure water hammer if there is an inherent fault within the house plumbing

[FZR400RRSP]

Interesting thread.
We've been getting loud banging from the pipes when things are turned on/off since the new kitchen was installed a year or so ago.
Getting into the pipe box to clip them would mean punching a hole in the wall and subsequent redecorating.
I'm now wondering if the kitchen fitters turned the mains stopcock open to full, when it wasn't before.
It makes sense that this is the cause, as I also noticed an increase in cold water pressure since the kitchen was done.
I'll try closing the stopcock a bit.
Here's hoping.

[961]

Originally Posted by FZR400RRSP

Interesting thread.
We've been getting loud banging from the pipes when things are turned on/off since the new kitchen was installed a year or so ago.
Getting into the pipe box to clip them would mean punching a hole in the wall and subsequent redecorating.
I'm now wondering if the kitchen fitters turned the mains stopcock open to full, when it wasn't before.
It makes sense that this is the cause, as I also noticed an increase in cold water pressure since the kitchen was done.
I'll try closing the stopcock a bit.
Here's hoping.

In rural areas it depends a lot on where you live (he opined) For example, we live in a valley where mains piping has been renewed with plastic in the last ten years. We have hills around and mains pressure in the village is high. While I guess it's possible to install a pressure valve by the stop cock in practical terms it's a no brainer to turn the stop cock down to control the incoming pressure. I know you shouldn't do this because in theory the water will wear the stop cock, but ten years down the line the thing is still working fine. This idea also has the advantage that if, one day, you come to need to turn the stop cock off in an emergency you won't find it stuck solid in the fully open position. Always assuming you do actually operate it occasionally

[neilios]

Originally Posted by 961

Did with us because of excessive mains pressure

I agree it won't cure water hammer if there is an inherent fault within the house plumbing

Closing the stop tap doesn't reduce the pressure just the flow rate,your problem was caused by a worn washer on the stem,or worn gland nut assembly,turning the tap can alleviate the problem...

[961]

Originally Posted by neilios

Closing the stop tap doesn't reduce the pressure just the flow rate,your problem was caused by a worn washer on the stem,or worn gland nut assembly,turning the tap can alleviate the problem...

OK. Reducing the flow rate solved our problem throughout the house

Are you suggesting all our appliances suddenly developed worn washers or worn gland nuts?

During the 10 years in question various washers and gland nuts have been replaced at odd times as they have developed wear and started to drip or it became obvious they were not operating smoothly. But at no time did water hammer occur

Perhaps you have a different name for excessive mains pressure that causes reverberation when a tap is closed?

[neilios]

Why is it when someone posts a question to about a diy problem a pro tradesman answers then a few diy heads butt in with a load of cobblers,i'm not answering anymore,bloody annoying...

[961]

Originally Posted by neilios

Why is it when someone posts a question to about a diy problem a pro tradesman answers then a few diy heads butt in with a load of cobblers,i'm not answering anymore,bloody annoying...

OK, so sorry old thing!

It may be total and utter cobblers but the thing is....it worked for me

[shoestring25]

if the pipes were clipped in properly it shouldnt matter what the water pressure is they wouldnt be allowed to move about and rattle

[ichikiriyama]

Update. Closed the stopcock and has made no difference.

Any thoughts on where to go from here?

[961]

Originally Posted by ichikiriyama

Update. Closed the stopcock and has made no difference.

Any thoughts on where to go from here?

As Neilios suggests look for loose piping etc

[Cliff]

As a DIYer I have the following comments.

Water hammer is usually caused by the pipes in your house not being secured properly with pipe clips. When you shut off the cold water quickly they move and can start to oscillate. If there is air in the the pipe (water lock) this can also make the situation worse as air can be compressed and acts like a spring.
If the water pressure has been increased then this may be why your problem has started suddenly (or a loose pipe).

You cannot reduce the pressure by turning the stop cock (that is flow rate). the only way is a pressure reducer- as posted above.

Also check if you have any toilet cisterns or ball cock valves in the loft, which while closing slowly, can start to vibrate

[shoestring25]

As Neilios suggests look for loose piping etc

as i suggested

[neilios]

Originally Posted by ichikiriyama

Update. Closed the stopcock and has made no difference.

Any thoughts on where to go from here?

There a suprise...I'm giving out awards for the silliest suggestions..

[ichikiriyama]

Originally Posted by neilios

The dynamic pressure from the incoming mains might have changed,there's no way a householder would know,or it could be a faulty tap,shower valve or even a toilet inlet valve causing the water hammer..

So they could be faulty even though the water hammer is not caused when using those individual plumbing devices?

Come to think of it, I did replace the valve on the toilet a few months ago. Could it be that the valve was not fitted correctly?

[paulyoung666]

Originally Posted by ichikiriyama

Come to think of it, I did replace the valve on the toilet a few months ago. Could it be that the valve was not fitted correctly?

quite possibly , if the valve is shutting off very suddenly it can cause water hammer , basically shockwaves in the pipework , in severe cases it is possible for pipework to come apart because of it .....

[its_all_Greek]

Self-righteousness (also called sanctimoniousness, sententiousness, a holier-than-thou attitudes) is a feeling of (usually) smug moral superiority derived from a sense that one's beliefs, actions, or affiliations are of greater virtue than those of the average person.

[ichikiriyama]

Originally Posted by its_all_Greek

Ha.

[Geege]

It seems there is air in the central heating system. Have you never bled the radiators before? Try this.

Any signs of staining or discolouration or leaks in any pipes? Does your boiler pressure drop?

[shoestring25]

hes on about the cold tap causing the problem so its not anything to do with the central heating

[ichikiriyama]

Originally Posted by shoestring25

hes on about the cold tap causing the problem so its not anything to do with the central heating

Yep.

[DJ Ovengloves]

Maybe because you're talking nonsense!

A reduction of flow rate from the rising main reduces the pressure within the house - this is basic physics and simply can not be argued with ("pro" or not), this can and does fix water hammer in some instances.

I am not in anyway stating water hammer can not be caused by a miriad of other issues (including the scenario you describe), loose pipes and even the addition of a tap with a ceramic washer, but reducing the incoming mains pressure by reducing flow-rate is a tried and tested method of sometimes reducing hammer.

Originally Posted by neilios

Closing the stop tap doesn't reduce the pressure just the flow rate,your problem was caused by a worn washer on the stem,or worn gland nut assembly,turning the tap can alleviate the problem...

Originally Posted by neilios

Why is it when someone posts a question to about a diy problem a pro tradesman answers then a few diy heads butt in with a load of cobblers,i'm not answering anymore,bloody annoying...