drained system to put in new rad in bathroom had to move pipes filled system back up bleed all rads and vent next to water cylinder went to start up boiler and loud knocks and bangs from it after a few mins pump running fine its got a air lock please please can some one help is it just to run it slowly and keep bleeding it or is there another less obvious way

stuart, April 2007

with system off remove the large screw in centre of pump to bleed pump then replace screw and try then sounds like pump has air lock

hi-spec plumbing, April 2007