Set Square wrote:
It seems to me that your system needs a really good flush out, and then
needs to have inhibitor added. By far the best way to flush it out -
particularly with summer coming on - is to remove the rads and take them
outside and give then a good flush out with a hosepipe. While they're off,
flush the flow and return pipes by keeping the header tank full and opening
each radiator valve in turn (with a bowl under it to catch the water!).
Incidentally, take great care not to spill any black sludge from the
radiators on your carpets - it makes a pretty indellible dye!

If you get a plumber in, he'll probably want to charge you an arm and a leg
for doing a power flush. However, the method I have described is far
cheaper - and probably more effective.

That's fantastic information, many thanks Set Square, I'll give that a
go. Incidentally, with me being a complete newbie, where does one put
the corrosion inhibitor? Does it simply pour into the header tank?

Thanks again,

Bob