FOG HORN WHEN I FLUSH THE LOO!!! Drainage and wastage systems and plumbing help, advice and answers

[Fedupwithfoghorn]

Hi we have had a problem developing for quite some time now - if we flush our upstairs loo we get a fog horn sound made worse when running the cold water. The pipes then seem to knock and I can feel them going to the sink and bath - we've tried to contact a plumber but they are as rare as hen's teeth in my neck of the woods!
Any help would be gratefully received......
I had thought maybe we should drain the cold water tank as I suspected an air lock so would this help or hinder.....calling all DIY gurus!!!

Cheers

[stoneyboy]

Fedupwithfoghorn,
If you have a mains fed loo and the cold water is the mains tap have a look and see if you have a non- return valve in the mains in pipe.
If both are fed from the cold tank replace the ball valve on the cold water tank.
end

[htg engineer]

Replace ball valve in toilet cistern.


htg