Currently taking the CH apart and updating various things. The system
and pipework are over 30 years old and we live in a very hard water
area.

Had to remove a section of incoming main (15mm) and to my astonishment
it was virtually limescale free. There was a very fine layer of
powdery limescale but you could wipe this off with a finger.

Also, removing a section of pipework from the radiator circuit showed
that to have only a very fine layer of magnetite. The water removed
from the rads had a slight dark "tinge" to it but nothing severe.

The pipework genuinely hasn't been touched in 30+ years. The previous
owner stated that he did nothing to the CH system apart from hoover
the boiler out every year.

I'm starting to think all this stuff about limescale blocking pipes is
a load of rubbish.

Kettles and appliances yes (I have seen that) but pipework no..I
assume heat makes the difference?

Has anyone any first hand experience of pipework becoming seriously
scaled up or is it a myth?

Can anyone explain why my 30 year old pipework is scale free?

sponix