Pipes making a humming sound

[Joeylegend]

Does any one know what would cause this?

When you turn on the hot water tap upstairs or downstairs the mains feed pipe coming up from downstairs vibrates against the rafters and then makes a humming noise so loud it can be heard outside in the street.

 

[BoxBasher]

Does it sound like a bugle/horn?

Pound to a pinch of s**t its your ballvalve. Re-washer or replace the whole thing. Relatively cheap and simple job.

 

[Joeylegend]

Cheers , It does sound like a horn( it was funny at the start but it is now a bit annoying. I will look at your suggestion tonight.

If it is the ballvalve in the roofspace tank, howcome it does not seem to do it when the cold is run upstairs or the loo is flushed?

 

[BoxBasher]

Depends on your setup. I'm making the assumption that it is the ball valve on the tank that supplies water to your cylinder. When you run hot water it causes the level in the tank to drop, making the ballvalve open and the washer vibrate.

Is your cold water mains fed? That would explain the lack of noise when cold run. (Easiest way to tell is put thumb over tap. If it stops you are tank fed, if it sprays water everywhere it is mains pressure. Be prepared for the spray.)

 

[Joeylegend]

No the cold is not direct from the mains. Cold upstairs is from the tank .there is a vibration from the mains pipe coming from downstairs going to the tank in roof space.

I can put my hand on the mains pipe(which leads to the tank) in the bathroom and feel it.

 

[Joeylegend]

It was the ball valve, I bought a new ball valve and replaced it and the noise went away. Well done boxbasher.

A tip I discovered while doing this was to tie the old ball valve up for the day(not letting any water from the mains into the tank) and carry out the every day duties that would have caused the strange sound. I discovered that the sound had gone away and when I untied the ball valve again the noise came back. Therefore I knew it was the ball valve.