Hi all

Some of my downstairs radiators seem to have sludge build-up as they
are cooler at the bottom and middle than the top and ends. Having read
previous posts, I am planning on trying a chemical sludge remover
first, and if that does not give good enough results I will try
flushing the radiators with a hose in the garden.

The instructions for the sludge removing products say to drain and
flush the system after the chemical has been used. The trouble is that
there are lots of inverted loops in my system. There are eight
radiators downstairs, each fed by pipes dropping down from the first
floor. Does this mean I need to drain each of the eight inverted loops
individually? Or
is possible to drain/flush the system by opening just one drain-cock
downstairs while running the pump and letting clean water enter the
system via the header tank?

Each of the radiators downstairs has a drain-cock built into the
radiator valve. Is this drain-cock for draining the radiator or for
draining the pipework? With the radiator valves open, the water must
be coming from both the rads and the pipework. With the radiator
valves shut, if I open the drain-cock is the water coming just from
the radiator or just from the pipework?

I have been looking at the Fernox products. The description of the F3
cleaner (http://www.fernox.com/?cccpage=restorer_500ml&sub=1) is
identical to the description of the Heavy Duty Central Heating
Restorer (http://www.fernox.com/?cccpage=heavy...estorer&sub=1),
does anyone know the difference between these two products?

thanks

Julian