heating system (plumbers?)

[chaz]

you need all the rad valve fully open, then open a drain off cock, when the water stops open the air bleed valves upstairs then on the down stairs rads or you could shut all the valves and leave the rads full, but the pipes wont drain off till you disconnect the valves on the one you're taking off, but with 8mm pipes there wont be that much??
you can get inhibitor that you inject into a rad by taking a bung out of the top of a rad, might be worth it in time.