Richard Marx wrote:

Final question: Is there a quick, easy, low-cost anti-sludge treatment I can
add to the system to prevent the new valve ceising up?

Companies like Sentinel and Fernox make both corrosion inhibitors which
should be used to prevent sludge in the first place (which is basically
bits of decomposed heating system held in suspension!), and also
desludgers that can be used to clean a system.

You *must* have the former in there all the time to keep things running
well. Whether the desludger is needed will depend on how badly sludged
your system is (cool patches at the bottom middle sections of radiators
would be a good clue there is a pile of crap in there).

If you use the desludgers you add them to the system for a couple of
weeks, then drain down, flush through a few times, refill and add fresh
inhibitor.

Might be worth googling back on this group for Andy Hall's posts on a
procedure for doing your own system flush.

--
Cheers,

John.

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