"Graham." wrote in message
...


Filling a system and not firing it right away to remove oxygen leads to
rust. A boiler
should never be drained -refilled and let sit all summer withouts days
of high firing. There are stop leak products but the metal is thin.

My system has never had inhibitor added, not for the last 30 years anyway.
Not been drained for over 10 years either.
Open tank system so I suppose some new water would have been introduced to
replace evaporation.

My thinking is the water will be pretty inert by now. What do you think?

--
Graham.

%Profound_observation%

I don't know Graham, but if the pipes and rads I have changed over the years
are anything to go by, you will have a lot of sludge, and it can take an
awful lot of flushing to get it out as the coppery black goo is pretty
heavy. As to corrosion, obviously the local water supply varies in hardness
and mineral content, but even this is pretty closely controlled these days.
There are probably electrical/ionic effects that can cause local corrosion
if all the metal is not uniform, in any system. But not being chemist or
engineer these are only assumptions.

Cheers,
S