Can anybody give advice, i drained the central heating system today and fitted 1 TRV downstairs and 4 TRV's upstairs, filled up the system, added inhibitor, bled the radiators and now the upstairs radiators are hot but downstairs are cold, there is air circulating around when the pump is running in the airing cupboard, there is hot water at the bleed off point under the downstairs floor.
Any ideas how to get rid if the air
Any ideas how to get rid if the air