Sucking air problem with radiators

[photogr22]

Hi There,

Just moved into my new house and 3 radiators dont heat up. just tried to bleed them. but instead of water or air coming out. I could here air being sucked in.

Instantly thought this was not right. but I do not have a clue how to resolve this. can someone please help me.before the wife kills me for tampering with thing i know nothing about.

thanks in advance....db

 

[meldrew's_mate]

Sealed system? Top-up the pressure, and rebleed, top-up again.

Open vent? Check for water in the header tank.
Are the non working rads upstairs?
Try bleeding with the heating off (pump stopped)

If that doesn't sort it you may be into blocked cold feed pipe territory.