On Mon, 26 Dec 2005 22:19:28 GMT, "john"
wrote:




Andy - I wish I had your confidence that this is all that is needed. I have
seen pictures of the hard calcium like deposits and wonder if flushing in
the way you describe is adequate.

Well.... it worked for me. I would agree that it works better if
you have a sealed system and hence can use the mains pressure. Having
said that, it's pretty easy to create this for the purposes of
cleaning. Simply fit a compression stop end to the vent pipe, then
cut the feed pipe and fit a stop end to that as well. You can remove
these later, replacing the one on the feed side with a compression
coupler. Put in a filling loop at a convenient place.

You shouldn't have scale deposits in the pipes of a CH system at all
unless it has been leaking because the same water is recirculated.

It's pretty easy to see whether the microbore tube has restrictions
because the flow rate won't be there.

Ultimately, you could resort to power flushing, renting a machine and
using hot water with chemical flushing agent.


Incidentally - on my system - which is open vented - I have made up a pipe
to screw into the top plug hole of the radiator that is then attached to my
hose pipe. I give an occasional blast back through the system and out
through other drains - keeping an eye on the header tank. (I do this after
cleaning a radiator)


If the boiler is suitable, why not change it to sealed? very easy to
do.


--

..andy