One Radiator not working

[chanmachmagi]

I recently had a service from British Gas. All was fine. Iasked him about the clanking sound in the boiler (halstead best 60) and he advised me to drain two bucket loads of water (stop cock jammed in loft) and add some silencer. (Setinox 2000) I duly did this and the clanking sound stopped.

I then went round and bled all the rads.
The problem.
The rad in the downstairs bathroom and kitchen (both from the same dropdown feed) remain stone cold. Including the pipes that feed them.

I thought it might be an airlock and have given them both a good (half bucket) further bleeding. Some warm water was drawn down the down pipe.

I have also turned all the other rads off. This caused the bathroom and kitchen rads to come on. But... when I turned the others back on. These two turned off again.

Do I need to balance? They all worked fine previosly.

 

[chanmachmagi]

Have sorted it, just turned all the others off and left the kitchen one on all day. Seems to have cleared the air block.