the answer is No!
you need the boiler going so the water is pumped around the system and when you open the bleed nipple it forces the air out. Half turn open should be enough don't open too far it'll come out then you will have a problem trying to battle hot water getting the valve back in. I turn mine half a turn and a wee bit then wiggle the bleeed nipple and can hear the air once water comes out shut valve off.
ensure carpets and other stainable floor covering are covered well below and about 2feet past the rad as sometime the water coming from rad is black and stains are not removable.
Nobby., February 2009
