uksparky,
Many thanks for your considered and obviously knowledgeable resonse. Are you involved in the plumbing side in some way?
Any way, the water is now running clear as I dumped 2 bottles of bleach into the tank and then thoroughly flushed the system through. I could have lived with the muddy copper colour but the growth was repulsive, almost like little bits of stringy brown moss. I also discovered a weep at the bottom of the hot water cylinder which may have permitted air to enter. Whilst the bleach has cleared the water, it is not yet reasonable to conclude that the growth has been dealt with.
[This message has been edited by lyledunn (edited 10-01-2004).]
