Posted by Harold Kestenholz - Hydronic Network on November 13, 2001 at 18:37:21:
In Reply to: cast iron radiators posted by John on November 13, 2001 at 18:23:03:
When the bleed is opened, if there is air at the valve, air will come out, if there is half air and half water at that level, both will come out. If there is just water there, the radiator does not need to be bled.
If nothing comes out, the valve can be removed to rod out the hole so the bleed valve can do its job.