My upstairs cistern makes a loud foghorn noise when flushed and then a longer, louder similar noise as it gets nearly full. It is an amazingly loud noise which can be heard from the street. When I run the cold tap in the bathroom, it stops for a bit but I think that's because it's delaying the filling up of the cistern. Any ideas? It's your bog standard (if you'll pardon the pun) armitage shanks ceramic cistern with a pull handle on the front.

Annette Chapman, November 2007

new diphram required in ball vaulve

kristin jennett, November 2007

A phenomenon known as Water Hammer.
Basically resonance in the pipes. Something is vibrating under the pressure of water going into your cistern.
Usually renewing the ball valve washer sorts the problem out.
After that its a case of securing any loose pipes and reducing the pressure of water going to the cistern.
When you turn on another tap reduction of pressure is exactly what's happening and that's why it often stops the resonance

Slugbabydotcom, November 2007