I have been trying to bleed my radiators tonight and the top floor (a
3 story house) is just about as full of air as it could be. I have
bled loads out but after running downstairs 3 or 4 times to top up
the pressure in the system I have given up for the night. It occurs
to me that I am probably getting this because I don't have enough (if
any) treatment in the system. the house is 18 months old and I would
bet the developer didn't put anything in....................the water
is nice and clear what is coming out.

I would like some advice as to what I need to put in - I have to
replace one of the bleed valves (if that's not what they are called I
would appreciate knowing what it is called so I don't look silly when
asking for one!) as it doesn't tighten properly and I understand you
can put it in to the system that way - perfect as I have so much air
space in there!!

Any tips gratefully received

Angela