I installed a new rad a few days ago and when I refilled the system it took approx 4 hrs to bleed all the air out. There seemed to be very little pressure to push the air out and the feed tank in the loft level dropped very slowly,is it possible there may be a blockage in the feed pipe the may restrict the filling pressure. There are 10 rads and hot water tank with a boiler (there's no bleed valves on the boiler only a drain tap) downstairs in my system and I started bleeding the furthest rad away from the feed tank and gradually worked my way back to the closest upstairs. Anyone have any thought's why it take's so long to fill or is there a better way to bleed this type of system.
