boiler pump not sounding too healthy

[mattjohnson]

right well yesterday dad has been working in the kitchen taking out the old one and putting in a new one and sealed off the plumbing for the small radiator in the kitchen and all that, upstairs in our airing cuboard we have a smallish green cased pump ( im not a plumber or know any know how on anything ) it keeps making screaming noises about every minute, its only happened after dad has messed about with the plumbing though please can someone help, its been keeping me up since about 3 in the morning

 

[namsag]

Its air turn system off and bleed any air bleeds you can find check in airing cupboard you may have some bleed points there as well