Humming from pipes

[sam.r]

Any ideas why the pipes (cold water) is making a really bad humming noise?

It stops when you open a tap.

Is it to do with pressure?

[Murray993]

I think you may want to talk to the stag do in Brighton about taping the cold pipes.....

[Poledriver]

It's simple..............They are humming because they don't know the words!

HTH!

[Neil_H]

sam.r said:

Any ideas why the pipes (cold water) is making a really bad humming noise?

It stops when you open a tap.

Is it to do with pressure?

Is it a "hmmmmmmm" noise or more of a "hhhhhhhnnnnnnnnnhhhhhhnnnnnnn"?

[sleep envy]

or is it a hhhhhhmmmmmmmmmmmmmmmmmmmmmmmmmvvvvvvvvvvvvv?

Edited by sleep envy on Friday 15th May 15:42

[sam.r]

Neil_H said:

sam.r said:

Any ideas why the pipes (cold water) is making a really bad humming noise?

It stops when you open a tap.

Is it to do with pressure?

Is it a "hmmmmmmm" noise or more of a "hhhhhhhnnnnnnnnnhhhhhhnnnnnnn"?

The second one...

[sam.r]

Hmmmmmmm been moved to Homes, Gardens and DIY....

Helloooooooo anybody in here???????????

[Ferg]

It's water hammer.
Badly clipped pipes, roof tank ballvalve needs replacement... one of those.

[sam.r]

Is it just the pipes vibrating?

I'll get up there and add some more clips..

Thanks for the advice.

[Ferg]

I'd look carefully at the roof-tank ballvalve. In fact I'd just replace it I think.

[sam.r]

Ah missed that on your last post.

It has just been replaced as the old one didnt stop the water...

This one lets water in faster than the last, I guess swapping it back for the same as the last one would solve it then.

Thanks.

[Ferg]

Hmmm... not sure what it's been replaced with.
I would expect it to be a brass Part 2 ballvalve. The speed it's filling the tank CAN cause water hammer because the force of the water coming in creates waves on the surface of the water making the ballfloat move up and down creating an on/off/onn/off action with the valve.

[sam.r]

Yep thats what it sounds like its doing.

[Simpo Two]

In which case perhaps adjusting the pressure of the mains supply slightly (stopcock under sink) might help.

WC cisterns now have hi-tech alternatives to ball-valves; is there nothing designed after 1860 for header tanks?

[Ferg]

Simpo Two said:

In which case perhaps adjusting the pressure of the mains supply slightly (stopcock under sink) might help.

Flow, not pressure.
Reducing the flow at the rising main might cure it, but you'd reduce flow at every cold too.

Simpo Two said:

WC cisterns now have hi-tech alternatives to ball-valves; is there nothing designed after 1860 for header tanks?

Modern toilet cisterns only use an equilibrium ballvalve constructed from plastic. Equilibrium valves are by no means a new invention and are used primarily because they fill at full bore, but shut off silently (in theory). You could fit an equilibrium valve in the roof tank, but it's a case of 'why spend a lot of money on one, when just fitting the correct, cheaper, valve will do?'.
Treat the cause, not the symptoms.

[Simpo Two]

Ferg said:

Flow, not pressure.

Fair point. I lowered the flow on my rising main a little because every time I turned on the kitchen tap it blasted me in the face!

Ferg said:

Modern toilet cisterns only use an equilibrium ballvalve constructed from plastic.

Is that what my Grohe ones have? They're certainly a masterpiece of design inside; I didn't realise there was still a ballvalve lurking in there somwhere, but they're very good.

[PhantomHumper]

http://news.bbc.co.uk/1/hi/uk/8056284.stm

[Simpo Two]

PhantomHumper said:

http://news.bbc.co.uk/1/hi/uk/8056284.stm

But in this case the humming will stop when the tank is full.