"even when the stop cock in the house is closed the whistle is very loud or when there is no flow the whistle is very loud but more so at night time,the onlyway to silence this whistle is to turn off the stop cock out on the footpath."
Is there a way to check for flow through your plumbing when the "stock cock in the house" is closed? Can you mark your water meter needle position with a felt pen, then let your plumbing whistle for a while (without using any water) and check the needle position later to see if the needle has moved relative to the mark.
I think what might be happening is that the stop cock in your house is leaking, so closing it doesn't make much of a difference if the flow rate is small and the leakage is going into the toilet in your house (or one of the toilets if you have more than one). Because of the way toilet fill valves work, they can open and close VERY rapidly, causing a noise that sounds like anything from a whistle to a fog horn. Take the tank lid off your toilet tank(s) and see if the water level in the tank is at the top of the overflow spout. If so, you need to replace the rubber diaphragm in that toilet tank's fill valve.
Last edited by Nestor_Kelebay; 08-15-2008 at 02:49 AM.