Hi, We've finally got around to bleeding a radiator which has been cold at the top and warm at the bottom since we moved into our house 18 months ago... previous owner didn't leave any keys and we've only just got hold of one. When I bled it I got the expected hissing sound for about 10-15 seconds, then it died down. No water came out. I re-tightened the screw, left it for a few hours, tried again. Same thing happens. I've been doing this two or three times a day for a few days, get a bit of air coming out each time. No water yet. As a total layman, my guess as to why this is is that there's so much air in the radiator, the pressure isn't enough to push it all out in one go. Am I right, and if so will I eventually get all the air out by doing what I'm doing, or am I wasting my time? Is there anything else I can do to help it along, or anything I should be doing? (I've discovered it's best to do it with the heating turned off, to avoid getting more air into the system.) Our boiler is a gas Worcester 28CDi. It's on the ground floor of the house, the problem radiator is on the second floor. Any help hugely appreciated.